Moravian Sugar Cake

Preparation

1. Step 1

   Make the cake: In a medium pot, bring 2 quarts of water to a boil over high heat. Add the cubed potatoes, reduce the heat to medium and boil until fork-tender, about 20 minutes.

2. Step 2

   Meanwhile, grease one large bowl and an 8-by-8-inch square cake pan with butter.

3. Step 3

   Turn off the heat, drain the potatoes and return them to the warm pot to dry out for about 30 seconds. Mash the potatoes with a fork or a potato masher until very smooth, then measure out 1 cup/190 grams of the mashed potatoes. (Remove any leftover potato from the pot to save or discard.) Return the measured mashed potatoes to the pot, add the milk and whisk until very smooth. Set aside to cool slightly.

4. Step 4

   In the bowl of a stand mixer, stir together the lukewarm water, 1 tablespoon/15 grams of the sugar and all the yeast, and let sit for 5 minutes until foamy. Add the remaining ½ cup/100 grams sugar, plus the flour, mashed potato mixture, melted butter, egg and salt; mix with a wooden spoon or rubber spatula just until a shaggy dough forms.

5. Step 5

   Fit the mixer with the dough hook. On low speed, mix the dough for about 3 minutes, then use a spatula to scrape down the sides. Continue to mix until the dough is stretchy but still sticking to the hook, 2 to 3 minutes more. The mixture will look somewhere between cake batter and bread dough, and will be quite sticky to the touch.

6. Step 6

   With a bench scraper or flexible spatula, transfer the dough to the greased bowl, cover tightly with plastic wrap and let sit at room temperature for 30 to 40 minutes, until visibly puffier but not doubled in size. Set a small bowl of room temperature water off to the side.

7. Step 7

   Uncover the bowl (saving the plastic), and with a bench scraper or flexible spatula, transfer the dough to the greased cake pan. Using lightly damp hands, press the dough down into an even layer that reaches all corners of the pan. Cover with the plastic wrap and let sit for another 15 to 20 minutes, until the dough is a bit puffier.

8. Step 8

   While the dough rises in the pan, heat the oven to 350 degrees. Make the sugar topping: Combine the brown sugar, cinnamon and salt in a small bowl and set aside. In a separate microwave-safe bowl, microwave the butter in 15-second bursts until fully melted (or melt gently on the stove in a small pot). Let cool for at least 5 minutes (it should be pourable but not hot).

9. Step 9

   Uncover the dough and, using slightly damp fingertips, press down to make about 25 dimples all over the surface. You may need to go back over the dimples with redampened fingertips to make sure the indentation nearly reaches the bottom of the pan. Sprinkle the brown sugar mixture evenly over the top, patting down slightly to compact, and drizzle the melted butter all over the sugar.

10. Step 10

    Bake for 32 to 36 minutes, until the cake is slightly risen, the top is crisp and the sugar looks deeply golden. Let cool in the pan for 20 minutes.

11. Step 11

    Turn the warm cake out onto a cutting board and cut into 9 squares (or whatever size pieces you desire). This cake is best served warm, so if baking ahead of time, it can be reheated in the microwave for 30 seconds or in a 350-degree oven for 2 minutes. Store any leftovers wrapped tightly in plastic for up to 3 days.