Dirndl Kitchen

Make the Yeast Dough
2 Warm the milk to barely warm, add the yeast and let stand for 5 minutes for the yeast to activate.
3 Combine all dough ingredients in a bowl and knead for 8 minutes until combined and smooth. Cover with a reusable silicone bowl cover or damp cloth and let stand in a warm spot until doubled in size (about an hour).
Make Quark Filling
6 In the meantime, in a large bowl, beat together the sugar, butter and lemon zest and juice for the quark filling.
7 Gradually add in the eggs, then the flour, cornstarch and salt. Finally whisk in the quark (or light sour cream).
8 It's best to use all room temperature ingredients, so the quark filling doesn't take longer to bake, which could brown the yeast dough crust too much. Set the quark filling aside.
Make Apple Topping
11 Wash, peel, quarter and core the apples. Slice each quarter into 3 to 4 thick slices and place them in the bowl with the lemon juice to prevent them from browning. Add the cinnamon and toss to coat all the apple slices.
Make the Streusel Topping
14 Combine all streusel ingredients and break apart with your hands into streusel pieces. Set aside.
Assemble Cake
17 Preheat oven to 390 degrees Fahrenheit or 200 degrees Celsius (conventional setting). Prep a large baking sheet (16 by 12 inches or 40 by 30 cm is what I used) with either butter or non-stick cooking spray on the bottom and all sides. Cover the bottom in parchment paper. Spread out the doubled yeast dough to cover the entire baking sheet, using buttered hands. I also used a small bottle to help me roll out the dough more evenly (my rolling pin didn't fit in the baking sheet).
18 Spread the quark filling over the yeast dough.
19 Stick the apple slices into the quark filling, creating rows of apples.
20 Sprinkle the streusel over the top.
21 Bake for about 40 to 50 minutes or until the quark topping only just barely wiggles when you gently shake the baking sheet. I'd check at 40 minutes and then in 5-minute increments thereafer if it needs more time. A toothpick should also come out clean (it's good to have a couple of dry crumbs on it).
22 Let stand at room temperature for 1 hour to set up before serving. I love to serve some fresh whipped cream with this cake (I whip up 1 cup of heavy whipping cream with 2 Tbsp of powdered sugar and 1 tsp of vanilla extract).
23 To store, it's best to transfer to the fridge. I like to reheat the cake in the microwave for about 30 seconds if storing in the fridge. This cake also freezes incredibly well! You can microwave it for about a minute directly out of the freezer or simply let it sit out to thaw and enjoy.