Created by TeresaS on December 25, 2018
Step 1: Preheat oven to 425°F. Grease a 17X11 rimmed baking sheet with butter or cooking spray and line with parchment paper. Set aside.
Step 2: Combine 2 cups blueberries, the lemon juice, and 2 tablespoons granulated sugar in a medium bowl. Let sit 15 minutes or so until juices get a little syrupy. Combine flour, baking powder, and salt in another medium bowl. In a third medium bowl, beat egg whites with a mixer until soft peaks form.
Step 3: In a large bowl, whisk egg yolks, ricotta, remaining 6 tablespoons granulated sugar, 6 tablespoons melted butter, the lemon zest, and milk to blend. Gradually add dry ingredients, whisking until smooth. Fold in egg whites and blueberry-sugar mixture. Spread batter in prepared pan, smoothing top with a spatula.
Step 4: Bake until center is set and springs back when touched, 12 to 14 minutes. Remove pancake from oven. Set a rack 5 inches from heat and preheat broiler to high.
Step 5: Brush remaining 2 tablespoons butter over top of pancake. Broil until golden brown, 30 to 60 seconds. Cut pancake into 12 squares and dust with powdered sugar. Serve with the remaining 1 cup blueberries and maple syrup.