Amma's Hungarian Coffee Cake
WHAT YOU'LL NEED
Streusel
1/3 cup unbleached all-purpose flour
1 tablespoon superfine sugar
1 tablespoon packed light brown sugar
1/8 teaspoon ground cinnamon
Pinch of fine sea salt
2 tablespoons unsalted butter, melted and cooled
1/3 cup packed light brown sugar
2 tablespoons superfine sugar
1 1/2 teaspoons ground cinnamon
Unbleached all-purpose flour, for rolling the dough
1/2 recipe Yeasted Sour Cream Dough
4 tablespoons unsalted butter, well softened
1 large egg, well beaten
Softened unsalted butter, for the pan and brushing the dough
LET'S GET COOKING
To make the streusel: In a small bowl, mix the flour, superfine sugar, brown sugar, cinnamon, salt and butter with your fingers until combined and crumbly. Set aside.
In another small bowl, mix the brown sugar, superfine sugar, and cinnamon; set aside.
Lightly dust a work surface with flour. Place the dough on the work surface and dust lightly with flour. Roll out the dough into an 18 by 10-inch rectangle, with a long side facing you. Brush the well-softened butter over the surface, leaving a 1-inch border on all sides. Sprinkle the sugar mixture over the butter.
Starting at the top, tightly roll up the dough. Brush the empty border of dough with the beaten egg and pinch the seam closed. Roll the dough back and forth underneath your palms to seal the seam securely. Push the ends in on each side and roll again to stretch the log to 18 inches. Fold the dough roughly in half to form a U-shaped curve, with one side 3 inches longer than the other. Using the side of your hand, press a dent into the dough at its bend. Fold the longer length of dough over and around the shorter length twice to make two humps. Twist the dough lengths to create a third hump and tuck the two ends under the loaf. You should have a loaf about 9 inches long with 3 humps.
Generously butter a 9 by 5-inch loaf pan. Transfer the dough to the pan, being sure that the ends are well secured under it. Gently brush the softened butter all over the top of the dough. Sprinkle the streusel over the top, patting gently so it adheres. (Don't worry if some of the streusel falls into the corners or sides of the pan.) Place the loaf pan on a half-sheet pan.
Choose a warm spot in the kitchen for proofing. Slip the pan with the loaf pan into a tall kitchen plastic bag. Place a tall glass of hot water on either side of the loaf pan to keep the bag from touching the dough. Wave the bag to inflate it and tightly close it, trapping air in the bag. Let stand until the loaf rises 2 1/2 inches above the rim of the pan, about 45 minutes.
Position a rack in the center of the oven and preheat to 350 degrees F.
Carefully remove the glasses from the bag, then remove the pan. Bake the cake on the half-sheet pan until the top is deep golden brown, the dough in the crevices looks fully bakes, and an instant-read thermometer inserted into the center of the cake reads at least 195 degrees F, 45 to 50 minutes. If the loaf threatens to run, cover the top loosely with foil.
Cool in the pan on a wire rack for 10 minutes. Carefully unmold the cake onto the rack and let cool completely right side up.
To serve, slice the cake with a serrated knife.