Sour Cherry Coffee Cake

My husband sent me this recipe, because he reads Gothamist and they had it as a post. He also included the comment "this looks really f***ing good." Now that cherries are in season, maybe I will make him a really f***ing good cake!

1 1/3 C all-purpose flour
2 tsp baking powder
1/2 tsp ground cinnamon
1/2 tsp plus a pinch of salt
2 large eggs, separated
1 C (1 stick, 8 tbsp) unsalted butter
1 C plus 1 tbsp (packed) dark brown sugar
1/2 C whole milk
2 C pitted sour cherries
for the crumblies
1 C flour
1/2 C sugar
2 tsp ground cinnamon
2/3 C butter

Preheat your oven to 375 F.

Prepare a 9x9 square baking pan by buttering and flouring it.

Whisk together the flour, baking powder, cinnamon, and 1/8 tsp salt for the batter. Set aside.

In a separate bowl (I always use my KitchenAid for this), beat the egg whites with the pinch of salt until they form firm, glossy peaks. Transfer them to a separate bowl and set aside. (You don't have to clean the mixer bowl between steps, mind.)

Beat the butter and sugar together until creamy. Add the egg yolks and beat on medium speed for about 2 minutes more. Reduce the mixer speed to low and beat in half the dry ingredients, then all the milk, then the rest of the dry ingredients.

Take the bowl away from the mixture and stir in 1/4 of the egg whites with a spatula. Fold in the rest of the whites. Fold in the sour cherries.

Scrape the batter into the prepared pan.

Make the crumblies by mixing together the non-butter crumbly ingredients. Cut the butter into the mixture until the texture is crumbly. Spread over the cake batter.

Bake for about 55 minutes, or until a knife or cake tester comes out clean.

adapted from Baking: From My Home to Yours, by Dorie Greenspan