Species 011: Roasted Banana Cream Donuts with Speculoos Glaze

I’ve written previously about the importance of donuts in my family, and ever since I was reminded of the fact, I have been on a frightening donut bender. I recently went to Chicago to cheer on my younger sister at her first conference talk (she’s a butt-kicking med student with a penchant for research), and we may or may not have, but definitely did, eat about a dozen donuts in two days. I came home to fry up first some buttermilk cake donuts, then these—and I’m afraid this isn’t the end of it. I’m a woman possessed, and every flavor combination I dream up—every cream, glaze, caramel, syrup, and paste—everything, everything is seen through the donut lens.

On another recent trip to Austin for SXSW, I had the enlightening experience of eating at Kemuri Tatsu-ya. I’ve long been a fan of new-age Asian restaurants, but this Izakaya-come-Southern-smokehouse really blew my mind. I won’t list everything I ate—suffice it to say that jellyfish was one of the highlights. Just when I thought the meal couldn’t get any stranger or any better, I tried their Roasted Banana Pudding with Kokuto Crunch and Miso Caramel. I have a mild to moderate obsession with roasted banana to start, but the Kokuto (i.e. Japanese brown sugar) topping had a deliciously rich, spiced flavor that elevated the whole dessert. To top it off, the miso caramel provided just enough saltiness to temper the sweetness of the cream and crumble. I’ve had manic dreams about that dessert ever since… and I don’t care to analyze the psychology of that.

So in the calm eye of the perfect storm of my crazed obsessions, I decided to create a roasted banana cream-filled donut topped with the homely, spiced brown sugar flavor not of Kokuto but of Speculoos butter—one of my favorite spreadable alternative to peanut butter. I suppose it’s my way of dealing with my recent travel-induced obsessions, and luckily the results are delicious.

Primary Traits

Donuts in general are a labor of love, and the balance of flavors in these, as well as the hard-earned texture of the dough, takes time and patience. I decided to utilize the full trifecta of donut components—the dough, the filling, and the glaze—to pack the fullest flavor punch I could.

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Don’t feel guilty, sometimes you have to get down to business…

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Trait #1: Roasted Banana Pastry Cream

The idea for these donuts really pivoted around the roasted banana pudding I had in Austin, so I spent some time thinking about how I could make an analogous filling for the donuts. I’ve made dozens of batches of pastry cream, or crème pâtissière
 if you want to honor its French roots, and I love how it can act as a blank canvas for flavor delivered with a silky smooth texture. I decided to first infuse a batch of pastry cream with roasted bananas by bringing them up to a boil together then blend the whole thing to achieve a silky texture without straining out any of the banana. I had to thicken the cream with more cornstarch than I normally would have because the banana releases a good amount of moisture, but besides that it was some smooth pastry cream sailing.

The beauty of roasted banana is that the banana sugars caramelize and concentrate during the roasting process, so you’re left with a pure, deep, completely natural banana flavor without having to resort to extracts.

“The beauty of roasted banana is that the banana sugars caramelize and concentrate during the roasting process, so you’re left with a pure, deep, completely natural banana flavor without having to resort to extracts.”

Trait #2: Speculoos Glaze & Crumble

Last week, I covered my first batch of buttermilk cake donuts in a slathering of Speculoos glaze, and now I’d like to cover just about everything in it. Speculoos is a spiced shortcrust-type biscuit that I was first exposed to in the Netherlands. (Upon exposure, my diet changed to primarily Speculoos-based.) If you haven’t tried these biscuits, I highly recommend getting your hands on some and enjoying them with your morning cup of coffee—it’s the breakfast of champions. Biscoff is to Speculoos as Skippy’s is to peanut butter—it’s just a very widespread brand that you can surprisingly find in many American supermarkets. For this glaze, I mixed a copious amount of Biscoff’s Speculoos butter with the usual confectioner’s sugar and warm water glaze and added an extra dose of cinnamon to bring out the spiced flavor. After the donuts were glazed, I dumped them in some crushed Biscoff biscuits for a textural component.

Trait #3: Brioche Dough Donuts

Donut dough gives me anxiety, mostly because I am so darn picky about it and hate when it’s just a hair off, whether it’s too dry, too soggy, too cakey, too chewy—I’m a complete snob when it comes to donut dough with no donut-baking-prowess to back it up. But I’m trying to change that. For these donuts, I decided to tackle a brioche-style dough, which is the kind I enjoy eating the most. Brioche dough is enriched with lots of butter and milk, which gives it an incomparable flavor and soft, pillowy texture. Because of all the butter and milk, brioche takes a long time to rise (all that grease sits on the yeast and just weighs it down), so be prepared to plan ahead and prepare this dough the night before.

I decided to treat the dough right and fry it up in shortening instead of the usual vegetable oil, and I absolutely loved the frying experience. I found the shortening’s temperature easier to control and, thankfully, that it splattered and sputtered less as I was frying. Because of the thickness of these donuts, I fried at a lower temperature than I normally would (around 345º as opposed to the normal 360º) but still, the donuts were light and as minimally greasy as any fried thing can be.

I started with a recipe from The Washington Post because of its precision (i.e. measurements by weight) and balance between the egg yolks and butter. I was really pleased with the results and could not think of any modifications to make.

Resulting Species

The resulting cream-filled, glazed, and topped donuts are a real treat to eat. The deep, spiced flavor of the glaze and topping enhances the caramel-tones in the banana pastry cream, and the two flavors simply dance with each other. The brioche dough is soft, fluffy, and extremely flavorful, so it holds up well against the heavy-hitting roasted bananas and Speculoos. If you make the dough and filling the night before, the morning-time frying is really a breeze. Just remember how sublime a fresh donut is, and all will be well.

Until next time,

The Culinary Darwinist

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Roasted Banana Cream Donuts with Speculoos Glaze

Makes 12 medium filled donuts. This recipe is written by weight, and I really recommend against trying to measure it by volume, unless you want to get into some heavy and tedious arithmetic.

Ingredients

For the brioche donuts

114 grams whole milk
11 grams yeast
11 grams warm water (105º)

375 grams all purpose flour
56 grams sugar
7 grams kosher salt
1 tsp vanilla bean paste or extract
About 1.5 eggs plus 2.5 yolks
The goal is to have a total of 120 grams of egg mixture. The whole egg portion should weigh about 75 grams, while the pure yolk portion should weight about 45 grams. I'll let you decide how intense you'd like to be with weighing it all out.

143 grams softened butter

6 cups of shortening, for frying
Note: You'll need as much shortening to create a 2" depth of oil in your frying pan.

For the roasted banana cream

1 1/2 cups whole milk
1/4 tsp kosher salt
1/2 tsp vanilla bean paste or extract
Pinch of nutmeg

1/4 cup sugar
3 T cornstarch
2 tsp all purpose flour
4 egg yolks

2 small or 1 large ripe banana

For the Speculoos glaze & topping

1 1/2 cups confectioner's sugar
1/2 cup Biscoff Speculoos butter
1/2 tsp fine sea salt
1/2 tsp cinnamon
1/4 — 1/3 cup hot water

~20 Biscoff Speculoos biscuits crushed into a coarse dust

Method

Night before: Make the brioche dough

1. In a small saucepan, heat the milk until it reaches 105º. (If you don't want to use a thermometer, just stick your pinkie in it—it should feel warm but not burning.) Off heat, sprinkle the yeast over the milk, then add the warm water. Let the mixture sit for about 15 minutes, or until frothy and thickened slightly.
2. In the bowl of a stand mixer with the paddle attachment, combine the flour, sugar, salt, vanilla, nutmeg, eggs, and the thickened milk mixture. Mix on medium-low speed until you have a shaggy dough. Add the butter in three installments, waiting for the dough to smooth out between each.
3. Switch to the dough hook attachment, and beat the dough on medium-low speed for 15—20 minutes, or until the dough is elastic and passes the window-pane test. Transfer to a greased bowl and cover with a greased piece of plastic wrap in direct contact with the dough. Let it rise for 30 minutes at room temp, then move to the fridge to rise for 6—15 hours (i.e. overnight).

Optional but recommended night before: Make the pastry cream

1. Preheat your oven to 375º. Roast the bananas in their skin for 20 minutes, or until blackened and bubbling. Split the banana skin using two forks and scrape out the insides, mashing the pulp as much as you can. Discard the skins.
2. Combine the milk, salt, half the sugar, and vanilla in a medium saucepan over medium heat. While the mixture heats up, combine the egg yolks, cornstarch, flour, and the rest of the sugar in a bowl and whisk until light in color.
3. When the milk is scalded (this means it's hot but not yet simmering—use your pinky to judge "hotness"), temper the eggs by pouring adding a bit of the hot milk while whisking vigorously. Then add the egg mixture back to the pan with the rest of the hot milk and continue whisking constantly. Add the roasted bananas and continue whisking until the mixture has come to a boil and thickened so you can see your whisk tracks through it. Immediately pour the mixture into a blender and blend until smooth.
4. Transfer the cream to a bowl and cover with plastic wrap, in contact with the top of the cream. Refrigerate overnight, or until completely cold and set.

Prepare the donuts

1. The morning of, roll the chilled dough out to 1/2" thickness and cut into 3" rounds. Transfer the each round to its own individual parchment square for best results, or to a lightly floured parchment sheet. Proof the rounds at room temp for 1-3 hours, or in an 85º oven for 1 hour. The dough rounds should puff up and double in size.
2. If you didn't make the pastry cream the night before, make it while the donuts are rising. Otherwise, begin heating the shortening in a medium, heavy duty pot like a Dutch oven. Once the donuts are proofed and the oil has reached 345º on a candy thermometer, you can begin frying two donuts at a time. If you put each round on its own parchment square, you can just slide the parchment into the oil with the dough and pluck it out immediately. Fry each donut for about 3-4 minutes, or until a deep golden brown. Drain on a hefty bed of paper towels. Be sure to let the oil come up to temp between batches.
3. Make the glaze by whisking together the confectioner's sugar, Speculoos butter, salt, cinnamon, and hot water in a large bowl. While the donuts are still warm, dip them into the glaze, lift to let some of the excess run off, dip the top into the Speculoos crumble, then place onto a drying rack to set.
4. Once the donuts are glazed, load a piping bag with the narrow filling tip and the banana pastry cream. Fill each donut with a generous amount of the cream. You can use a paring knife to open up a small hole in the center of the donuts if you'd like. Eat the same day—day old donuts are no bueno. ∎