Step 1: Preheat your oven to 375°F (190°C). Grease and flour a 9-inch springform pan or a 9×9 inch baking dish.
Step 2: Prepare the strawberries. Gently wash the fresh strawberries, hull them, and slice them into halves or quarters, depending on their size. Toss them in a medium bowl with 2 tablespoons of granulated sugar and 1 tablespoon of all-purpose flour. Set aside.
Step 3: Make the streusel topping. In a separate bowl, combine 1/2 cup (100g) granulated sugar, 1/2 cup (60g) all-purpose flour, and 1/2 teaspoon ground cinnamon. Add 1/4 cup (56g) cold unsalted butter, cut into small cubes. Using your fingertips or a pastry blender, cut the butter into the flour mixture until coarse crumbs form. Place this mixture in the refrigerator.
Step 4: Prepare the cake batter. In a large bowl, cream together 1/2 cup (113g) softened unsalted butter and 1 cup (200g) granulated sugar with an electric mixer until light and fluffy, about 2-3 minutes. Beat in 2 large eggs, one at a time, mixing well after each addition. Add 1 teaspoon of vanilla extract.
Step 5: In a separate medium bowl, whisk together 1 1/2 cups (180g) all-purpose flour, 1 1/2 teaspoons baking powder, and 1/2 teaspoon salt. Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Do not overmix.
Step 6: Spoon the cake batter into the prepared baking dish and spread it evenly.
Step 7: Arrange the sugared strawberries over the top of the cake batter.
Step 8: Retrieve the streusel topping from the refrigerator and sprinkle it generously over the strawberries.
Step 9: Bake for 50-60 minutes, or until a wooden skewer inserted into the center of the cake (avoiding a strawberry) comes out clean. The top should be golden brown and the strawberries should be bubbling.
Step 10: Let the cake cool in the pan on a wire rack for at least 20-30 minutes before serving.