Yield: One 9 x 13–inch cake

Method:

Preheat the oven to 350ºF.

In a small bowl, combine 1/4 cup plus 2 tablespoons sugar with the cinnamon and 1/8 teaspoon salt. Grease the inside of a 9 x 13–inch cake pan with butter. Sprinkle the cinnamon sugar all over the inside of the pan. Shake out any excess sugar and save it for sprinkling over the cake. Set the pan aside.

In a stand mixer fitted with a paddle attachment, cream together the remaining granulated sugar, brown sugar, butter, lemon zest, vanilla, and nutmeg until very light and fluffy. Add the eggs one by one, allowing each one to incorporate completely before adding the next.

Whisk together the flour and baking powder in a bowl. Add a fourth of the flour mixture to the contents of the stand mixer and mix until just incorporated. Add a third of the buttermilk and mix until just incorporated. Continue mixing in alternating additions of flour mixture and buttermilk, ending with the final fourth of flour, until everything has been incorporated. Fold in 1 1/4 cups blueberries by hand.

Pour the batter into the prepared pan and use a spatula to level the top. Sprinkle with the reserved blueberries, followed by the remaining cinnamon sugar. Bake until the center of the cake springs back when gently pressed and a toothpick comes out clean, about 35 to 40 minutes. Serve warm.