Old-Fashioned Sour Cream Crumb Cake

INGREDIENTS

1/3 cup

packed dark or light brown sugar

1/2

cup all-purpose flour

and 1/2 teaspoons ground cinnamon

3 tbsp

unsalted butter, cold and cubed

and 1/3 cups (166g) all-purpose flour (measured correctly)

1 tsp

baking powder

1/4 tsp

baking soda

1/4 tsp

salt

1/2 cup

unsalted butter, softened to room temperature

3/4 cup

granulated sugar

large eggs, at room temperature

2 tsp

vanilla extract

1/2 cup

full-fat sour cream, at room temperature1