German Plum Cake with Streusel

Instructions

• Preheat the oven to 375 degrees F (190 degrees C). Grease a 10-inch springform pan.
• Lay plum slices flat in a single layer on paper towels to dehydrate slightly while you prepare the cake.
• Prepare almond crust: Mix almonds and sour cream in a saute pan. Gently saute over medium heat, being careful not to overcook, until almonds are lightly toasted, about 3 minutes. Remove from heat and add salt. Crush almonds manually into smaller pieces and distribute evenly across the bottom of the prepared pan.
• Prepare batter: mix marzipan and softened butter in a large bowl until mostly well blended. Mix in 6 tablespoons plus 1 teaspoon sugar and lemon zest until well combined. Add eggs, one at a time, mixing well after each addition.
• Whisk 1 1/2 cups plus 2 tablespoons flour with baking powder in a separate bowl. Gradually mix dry ingredients into wet ingredients until well combined.
• Place large spoonfuls of batter over the almond crust. Use the spoon to carefully push the top of the batter from the center of the pan outwards towards the edges, spreading evenly and being careful not to displace the almonds.
• Arrange multiple layers of plum slices over the batter, pressing down a bit after each layer, except the top one; you will likely have 3 to 4 plum layers.
• Prepare streusel: Mix sugar, melted butter, and vanilla in a bowl until well combined. Blend in 3/4 cup plus 1 tablespoon flour by hand until crumbly. Sprinkle streusel evenly over the cake.
• Bake on the center rack of the preheated oven until a toothpick inserted into the center comes out clean. Start checking for doneness at about 48 minutes, though it may take 10 minutes longer if the plums are very juicy. Do not overcook the streusel layer.
• Remove from the oven and cool on a wire rack for 5 minutes. Run a table knife around the edges to loosen. Remove sides and let cool completely before serving, about 30 minutes.