This recipe is easily doubled or tripled.
In a small saucepan over medium heat, cook blueberries, 2 tablespoons water, 1 tablespoon sugar, the lemon zest, and cinnamon, stirring frequently, until syrupy, about 5 minutes. Remove from heat.
Blend egg yolks and ricotta in a food processor until smooth. Add milk, flour, remaining 2 teaspoons sugar, baking powder, and salt, and process until completely blended. Pour into a mixing bowl.
Beat egg whites in another bowl until stiff peaks form; fold gently into batter.
Heat oil in a large nonstick skillet over medium-low heat. Pour batter into skillet by the quarter cup. Cook until tops are bubbly and dry-looking, about 4 minutes; turn and cook until golden brown, about 4 minutes more. Serve with blueberry sauce. Garnish with berries, if desired.