Beware. If you make this it will become your obsession. As it has become mine.
Smitten Kitchen posted it, and I (by some miracle) had all the ingredients. I took it to an all day beach party. Needless to say, it was extremely well received. The cake and I actually received a hero's welcome for saving the early morning beach folks from chocolate covered donuts from a box!
It is a very rare thing to bake something in this house that is as popular as this crumb cake has instantly become.
Blueberry Crumb Cake
Topping
5 Tablespoons all-purpose flour
1/2 cup granulated sugar
1 teaspoon ground cinnamon
4 Tablespoons unsalted butter
Cake
2 cups minus 1 Tablespoon all-purpose flour
2 teaspoons baking powder
1/2 teaspoon salt
3/4 cup granulated sugar
Zest of one lemon
1 large egg
1 teaspoon vanilla extract
1 pint fresh blueberries, clean and dry
1/2 cup whole milk
confectioner's sugar for dusting
Preheat oven to 375°F. Butter a 9-inch round baking pan (you really need 2" sides, since the berries may bubble over a bit) and dust it with flour. Line it with parchment paper.
Make the topping and set aside.
Whisk together flour, baking powder and salt in a medium bowl. In a large bowl, beat butter and sugar and zest together until light and fluffy. Add egg and vanilla and beat until combined. Beat 1/3 of the dry ingredients until just combined, followed by 1/2 the milk; repeat with remaining dry ingredients and milk, finishing with the last of the dry ingredients. The batter will be extremely stiff, but don't freak out. Gently fold in the blueberries just until evenly distributed.
Scoop the batter into the prepared pan and smooth it flat. Sprinkle with crumb topping and bake for 38-40 minutes or until a toothpick inserted into the center of the cake comes out batter free. Let the cake cool for at least 20 minutes before flipping it, removing parchment and placing on serving plate. Dust with confectioner's sugar if desired.
This keeps nicely for a few days, if you don't eat the whole thing the day you make it. Believe me, it will be a challenge since this cake is very inviting!
Also, it could also be doubled and baked in a 9x13 pan if you wanted to take it to a gathering.