Blueberry Crumb Cake

I love a good coffee cake, and this blueberry crumb cake doesn't disappoint. First there's the crunch and spice in the topping before hitting the moist crumb of the cake.

I decided to bake my "coffee cakes" in little espresso cups. After a quick spritz with cooking spray, I baked them for 25-30 minutes.

Recipe
Makes 8 servings (8x8 pan)

For the Crumbs:
5 tablespoons unsalted butter, at room temperature
¼ cup sugar
1/3 cup (packed) light brown sugar
1/3 cup all purpose flour
¼ teaspoon salt
½ cup chopped walnuts (I used pecans)

For the Cake:
1 pint (2 cups) blueberries (preferably fresh, or frozen, not thawed)
2 cups plus 2 teaspoons all-purpose flour
2 teaspoons baking powder
½ teaspoon baking soda
¼ teaspoon salt
¼ teaspoon ground cinnamon
1/8 teaspoon freshly grated nutmeg
2/3 cup sugar
grated zest of ½ lemon or ¼ orange
¾ stick (6 tablespoons) unsalted butter, at room temperature
2 large eggs, at room temperature
1 teaspoon pure vanilla extract