Rhubarb Crumble Buns with Strawberry Frosting

Super-soft, tangy buns.

I finished writing this post from my favorite corner of America: Michigan’s pinky finger. I led a bread and wine workshop at Left Foot Charley Winery wher we paired four six of their wines with six different breads. I baked focaccia and whole-grain rye Vollkornbrot, while Common Good Bakery baked four other incredible loaves for us. This event was a dream for me—pairing my two favorite fermented products. Thank you to Bryan, Kristy, Jessica, Meredith, and the entire Left Foot Charley team for hosting me, as well as to the 30 folks who attended. Especially my 20+ year friend Kate (Love you!) and her mom for joining and bringing a great group of friends. Stay tuned: I hope to do something like this workshop again!

Baking Up North.

While Up North, I also visited Dave Bos, the owner of Bos Winery, and we tasted through his wines at their charming Elk Rapids wine garden and tasting room. After Bryan Ulrich (of Left Foot Charley) and Sean O’Keefe (of Mari Vineyards) told me about Dave, I knew that I had to stop by, and I was blown away. Every bottle stunned me. More on these fabulous wines soon…

On to the recipe. Last week I snagged the first fresh local rhubarb of the year and jumped at the chance to bake with it. But I wasn’t dreaming of pie or cake—I had bread on my mind and I yearned for buns.

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Super-Soft Rhubarb Crumble Buns with Strawberry Frosting

This is a maximalist version of a swirled sweet bun. The first time I heard about the crumble buns from Angela Garbacz’s Goldenrod Pastries in Lincoln, Nebraska, my mouth began to water. I adore the easy, yum-tastice recipe from her lovely book Perfectly Golden. In here, I mash up my version of super-soft, squooshy sweet rolls, sprinkle them vanilla-bean sugar and chunks of tangy rhubarb. Since I loathe cooked strawberries yet wanted that strawberry-rhubarb flavor, freeze-dried strawberries give the icing punch. Good news—these buns are just as good the second day. Due to the high hydration and cooked flour paste (AKA tangzhong or Kochstück), these buns remain gooey and delicious.

Cooked Flour Paste

30 g high-protein all-purpose flour

120 g water

Dough

30 g sugar

Zest of 1 small lemon, finely grated

520 g high-protein all-purpose flour

2 teaspoons (7 g) instant yeast or 12 g fresh yeast

2 teaspoons (10 g) fine sea salt

120 g whole milk, cold

2 large eggs, cold

1 teaspoon vanilla extract

113 g (1 stick) butter, cold and cubed

All of the cooked flour paste

Filling

30 g (about 2 Tablespoons) butter, melted

80 g sugar

Seeds from 1 vanilla bean

2 Tablespoons all-purpose flour, divided

1/4 teaspoon fine sea salt

250 g rhubarb, trimmed and chopped into 1/4-inch dice (measured after trimming)

Crumble

90 g flour

60 g Sugar

Pinch of salt

50 g butter, room temperature

Strawberry Icing

10 g freeze-dried strawberries

90 g powdered sugar

Pinch of salt

20-30 g half & half or milk

Make the flour paste. In a small saucepan, whisk together the bread flour and water. Cook over medium heat, whisking constantly, until the mixture resembles thin mashed potatoes, about 4-5 minutes. Scrape onto a small plate and let cool for at least 5 minutes.

Mix, rest, and knead the dough. In the bowl of a stand mixer, add the sugar and lemon zest, then rub them together to release the fragrant oils from the zest. Add the bread flour, yeast, and salt, then whisk briefly to combine. Add the milk, eggs, vanilla extract, cubed butter, and the warm cooked flour paste. Fit the mixer with a dough hook and mix on the lowest speed for 4 minutes to combine. Turn the mixer off, cover the bowl, and let the dough rest for 20 minutes. Uncover the bowl and mix the dough on medium-low speed (speed 2 in a KitchenAid) for about 10 minutes. The luscious, soft dough should mostly gather around the hook and clear the sides of the bowl. A bit of the dough might stick to the side of the bowl. If that happens, scrape it down, then turn the mixer to low for a few seconds to mix that in. The dough should be slack and tacky, but not too sticky. Let the dough rest for 30 minutes at room temperature.

Ferment the dough. Grease a 9-inch square baking pan. Lightly grease your hands with cooking spray or a dribble of neutral oil, and pull the dough out of the mixer, put the dough into the baking pan, and press it down so that it’s in an even layer all the way to the corners of the pan. Cover the pan and put in the refrigerator for at least 3 hours, up to 18 hours.

Make the filling. Just before rolling out the dough, rub the sugar and vanilla bean seeds together, then whisk in 1 Tablespoon flour and the salt. Melt the butter. Toss the chopped rhubarb with 1 Tablespoon of flour.

Roll out and fill the dough. Take a bench scraper and release the cold dough from the sides of the baking pan. Generously flour your work surface and plop the dough onto it. It should come out as a near-perfect square. Dust the top of the dough with flour, then roll it out to a 16-inch by 16-inch square.

Brush the dough with the melted butter. Sprinkle the sugar mixture evenly all over the dough, except for about 1/2 inch along the side of the dough farthest away from you. Press the sugar into the dough a bit with your hands. Sprinkle the chopped rhubarb evenly over the sugar-covered dough.

Roll up and cut. Time to roll. Get the roll started by going along the edge of the dough closest to you and fold the dough over by about 1/4 inch. You should then be able to push and roll the dough into a nice swirl. Do not seal the edge.

Line a half sheet pan with parchment paper.

Take a serrated knifeand make small marks where you plan to slice the log: first, divide the dough into quarters, then divide each quarter into thirds. Using the knife, cut the dough it into 12 even rolls, approximately 1 1/3 inches wide. Place each roll on the lined half-sheet pan and tuck the tail of each roll underneath itself. Don’t fret if they look a bit higgledy-piggledy.

Proof the rolls until they're very puffy,and have risen at least 1 1/2 times their original size, about 45-90 minutes. (They may rise faster if you use fresh yeast.) If your house is very warm or very cold, the final proof could be faster or slower. Heat the oven to 350°F, with a rack on the middle level.

Make the crumble. While the rolls proof, whisk together the flour, sugar, and salt for the crumble. Dice the butter and rub it into the dry ingredients until the butter is fully incorporated and the mixture forms clumps. Place this mixture in the refrigerator until you need it.

Sprinkle each roll with with the crumble mixture just before baking. It may look like a lot of crumble, but these rolls will grow in the oven. Plus, you need some crumbly streusel in each bite.

Bake the rolls until puffed, golden brown, and read 195°F on an instant-read thermometer, 24-28 minutes. Place on a wire rack and cool for at least 30 minutes before icing and serving.

Make the icing. Grind the freeze-dried strawberries into a fine powder using a clean spice grinder or other device, them dump into a bowl. Whisk in the powdered sugar and salt. Add 20-30 g of milk or half & half and whisk until you have a smooth frosting that you can easily drizzle but that still holds its shape for a few seconds. Add additional liquid a little at a time to get the proper consistency.

Enjoy these gooey, soft, yet zippy rolls right away. They are still great on day 2, but might need a quick 5-8-second zap in the microwave to warm them up a bit.

Happy Baking,
Martin