To make the strawberry sauce:
Toss the lemon zest, lemon juice, and water into a blender. Add the strawberries and 6 tablespoons of the sugar. Process starting on low, then raise to medium speed. Blend for about 1 to 2 minutes until very smooth.
Transfer the puréed strawberries to a small saucepan. Whisk together the remaining 2 tablespoons of sugar with the cornstarch and add to the sauce. Cook over medium heat for about 15 minutes until the sauce thickens slightly.
Makes about 2-¼ cups of sauce.
To make the pancakes:
In a large mixing bowl whisk together the flour, sugar, baking powder, baking soda, and kosher salt.
Combine the buttermilk with the ricotta cheese, egg yolks, vanilla extract, and melted butter. Whisk to blend together.
In a small bowl beat the egg whites on medium speed until stiff peaks form, about 1 minute.
Add the buttermilk mixture to the dry ingredients, stirring just until combined; the batter will be stiff.
Using a spatula, gently fold in the egg whites.
Warm an electric griddle to 325-degrees.
When the griddle is hot, lightly brush it with additional butter. Scoop about ¼ cup of the batter onto the griddle, leaving enough room between each pancake to flip them. Top with some of the sliced strawberries pressing them gently into the pancake batter.
Cook until the pancakes are golden and the batter on top is set. Flip and continue cooking until the cakes are cooked through. These pancakes are thick and take a few minutes longer to cook through, about 5 minutes per side.
Serve with an extra touch of ricotta, warm strawberry sauce, and maple syrup plus a sprinkling of powdered sugar.
To keep the pancakes warm while you finish cooking, place the pancakes on a wire rack set over a rimmed baking sheet and place in a 200-degree oven.