Instructions

• Preheat the oven to 350°F (175°C). Lightly grease a 9-inch springform pan or line the bottom with parchment paper.
• In a large bowl combine 1 1/2 cups flour and 1 cup sugar.
• Add the 10 tablespoons grated frozen unsalted butter to the flour-sugar mixture. Use a fork, pastry cutter, or your fingertips to work the butter into the dry ingredients until the mixture resembles coarse crumbs.
• Scoop out 1/2 cup of this flour-sugar-butter mixture into a separate bowl. Add 1/2 cup slivered almonds to that bowl, stir to combine, and set aside (this is the streusel topping).
• To the remaining flour-sugar-butter mixture in the large bowl add 1/2 teaspoon baking powder, 1/2 teaspoon baking soda, and a pinch of salt. Stir to distribute the leavening and salt.
• Add 1/2 cup sour cream, 1 teaspoon vanilla, and 1 egg to the bowl with the dry mixture. Mix until a cohesive cake batter forms and no large dry streaks remain.
• Spread or press the cake batter evenly into the bottom of the prepared 9-inch springform pan, leaving about a 1-inch border of batter around the edge of the pan (do not spread batter all the way to the edge).
• In a small bowl, whisk together 6 ounces room-temperature cream cheese, 1 egg, 1/4 cup sugar, and 1 teaspoon vanilla until smooth.
• Spoon the cheesecake mixture into the center of the batter in the pan, spreading it gently but keeping about a 1-inch border of batter visible around the edge.
• Evenly distribute 2/3 cup mixed berries over the cheesecake layer. If using, dollop 2 tablespoons raspberry jam over the berries.
• Sprinkle the reserved streusel-and-almond mixture evenly over the berries and cheesecake layer.
• Bake in the preheated oven for about 50 minutes, until the top is golden and a toothpick inserted near the center comes out with only a few moist crumbs (the very center cheesecake may be slightly jiggly).
• Remove the pan from the oven and let the cake cool in the pan on a wire rack. When cooled to room temperature, release the springform ring. Chill before serving if desired.