Sour Cream Coffee Cake (with Crumb Topping)

Simple and classic, this buttery cinnamon crumb coffee cake is anything but plain! Sour cream ensures a moist, light (not overly dense) breakfast cake, and there’s double the brown sugar cinnamon crumb streusel. Enjoy a thick ribbon of streusel inside and plenty of crumbs on top, both made from the same mixture.

Ingredients

Cinnamon Crumb Mixture

2/3 cup (135g) packed dark or light brown sugar

3/4 cup (95g) all-purpose flour (spooned & leveled)

2 and 1/2 teaspoons ground cinnamon

6 Tablespoons (85g) unsalted butter, cold and cubed

Cake

1 and 1/3 cups (166g) all-purpose flour (spooned & leveled)

1 teaspoon baking powder

1/4 teaspoon baking soda

1/4 teaspoon salt

1/2 cup (113g) unsalted butter, softened to room temperature

3/4 cup (150g) granulated sugar

2 large eggs, at room temperature

2 teaspoons pure vanilla extract

1/2 cup (120g) full-fat sour cream, at room temperature*

2 Tablespoons (30ml) milk (any kind, dairy or nondairy, is fine)

Vanilla Icing (Optional)

1 cup (120g) confectioners’ sugar, sifted

1/2 teaspoon pure vanilla extract

2 Tablespoons (30ml) heavy cream or milk