01 -
Preheat oven to 175°C (350°F). Line an 8x8-inch metal baking pan with parchment paper, leaving a 2-inch overhang on each side. Note: Add an additional 10-20 minutes to baking time if using a glass dish.
02 -
Combine flour, both sugars, and salt (if using unsalted butter) in a medium bowl. Whisk to remove lumps. Add melted butter and stir until evenly combined. Toss the mixture with your fingertips to form large crumbs. Cover and set aside.
03 -
In a medium bowl, whisk melted butter, sugar, and vanilla until pale and fluffy. Add eggs one at a time, whisking after each addition until light and creamy. Mix in sour cream. In another bowl, whisk together flour, baking powder, and salt, then sift and fold into the wet mixture. Pour in milk and gently combine until the batter is uniform. Spread evenly into the prepared pan.
04 -
In a small bowl, mix flour and sugar, then sprinkle over the chopped strawberries. Toss to coat evenly. Scatter the strawberries over the batter in the pan.
05 -
Scatter clumps of the prepared crumb topping evenly over the strawberry layer to cover.
06 -
Bake in preheated oven for 40-50 minutes until the crumbs are golden and the cake feels firm. A toothpick inserted into the center should come out clean without wet batter.
07 -
Transfer the cake to a wire rack and let cool for at least 30 minutes before serving.