Blueberry Cruffins

What's a cruffin? A word that Brad created for this recipe, which is for blueberry "crumb muffins." It works. This treat started with an Ina Garten recipe for Blueberry Crumb Cake, which I decided to make into individual servings — hence the cruffin. It's a lovely recipe for this time of year when berry season is inching closer (although you can use frozen blueberries as well).

Blueberry Cruffin Recipe (makes 12 cruffins)

Streusel topping:
1/4 cup sugar
1/3 cup light brown sugar
1 tsp. cinnamon
1/8 tsp. nutmeg
1/4 lb. unsalted butter, melted (1 stick)
1 1/3 cup flour

Cake:
6 tbsp. unsalted butter, at room temp.
3/4 cup sugar
2 eggs, at room temp.
1 tsp. vanilla
1 tsp. lemon zest
2/3 cup sour cream
1 1/4 cup flour
1 tsp. baking powder
1/4 tsp. baking soda
1/2 tsp. salt
1 1/2 cup blueberries (fresh or frozen — if frozen, do not thaw)

Directions:

• If you're making cruffins, get your muffin tin ready with paper liners. If you'd like to make this in cake format, follow Ina's instructions for buttering/flouring the a cake pan. Note that I use more blueberries and lemon zest than Ina, so my ingredients is slightly different than hers.
• Preheat oven to 350 degrees.
• To make streusel, combine sugar, brown sugar, and spices. Pour in melted butter and mix well. Then add flour and mix until well-combined and crumbly. Set aside (and try not to eat too much of it).
• For the cake, cream the butter and sugar on high for about 4 minutes until light and fluffy. Reduce speed to low and add eggs, one at a time. Then add vanilla, lemon zest, and sour cream. (It's always a good sign when a baked good calls for sour cream.)
• In a separate bowl, sift together the flour, baking soda, baking powder, and salt. With the mixer on low, add flour mixture to batter and mix until just combined. Toss the blueberries in about a tablespoon of flour (so they don't sink to the bottom), and then gently fold in blueberries with a spatula.
• Fill each muffin cup about 2/3 full (you should be able to squeeze 12 muffins out of the batter). Then crumble streusel on each muffin — pat it down a bit to make sure the streusel sticks to the muffin. Don't be stingy with it! 
• Bake cruffins for 25-30 minutes until tester comes out clean. Cool and dust with confectioner's sugar (optional — I think the cake needs it but the cruffins don't necessarily).