2 c. (250 grams) plus 1 t. all-purpose flour
1 tablespoon baking powder
1 t. table salt
16 T. unsalted butter (2 sticks, 8 ounces or 225 grams), softened
3/4 c. (145 grams) packed light brown sugar
1/2 c. (100 grams) granulated sugar
3 large eggs
1 c. whole milk
3/4 (frozen) – 1 c. (fresh) blueberries, fresh or frozen (if frozen, do not defrost first as it tends to muddle in the batter)
Topping
1/2 c. blueberries, fresh or frozen (do not defrost)
1/4 c. (50 grams) granulated sugar
1/2 t. ground cinnamon
For the cake: Adjust oven rack to middle position and heat oven to 350 degrees. Grease and flour 13 by 9-inch baking pan.
Whisk two cups flour, baking powder, and salt together in medium bowl. With electric mixer, beat butter and sugars on medium-high speed until fluffy, about two minutes. Add eggs, one at a time, beating until just incorporated and scraping down bowl. Reduce speed to medium and beat in one-third of flour mixture until incorporated; beat in half of milk. Beat in half of remaining flour mixture, then remaining milk, and finally remaining flour mixture. Toss blueberries with remaining one teaspoon flour. Using rubber spatula, gently fold in blueberries. Spread batter into prepared pan.
For the topping:
Scatter blueberries over top of batter. Stir sugar and cinnamon together in small bowl and sprinkle over batter. Bake until toothpick inserted in center of cake comes out clean, 45 to 50 minutes. Cool in pan 20 minutes, then turn out and place on serving platter (topping side up). Serve warm or at room temperature. (Cake can be stored in airtight container at room temperature up to 3 days.)
