Toss the strawberries with the sugar and orange juice. Cover and let sit at room temperature for at least 30 minutes.
After the berries and sugar have macerated and become very juicy, remove 1/2 of the berry mixture, put it in a food processor and puree until smooth. Return it to the rest of the berries and reserve until ready to use.
Sift together all of the dry ingredients in a large bowl. In another bowl, combine the egg yolks, ricotta, milk and lemon zest and juice, and mix until it becomes homogeneous. Make a well in the dry ingredients, add the wet ingredients to the well and whisk until combined.
Preheat a griddle.
In another bowl, using a whisk or electric mixer, beat the egg whites with a pinch of salt to stiff peaks. Fold the egg whites into the flour mixture in thirds. Do this quickly and gently so the pancakes will be light and fluffy.
Melt small pats of butter onto the preheated griddle, and spread it around with a paper towel to remove any excess butter. Spoon or ladle the pancake batter onto the prepared griddle to desired size of the pancake. When the top of the pancake is full of holes, like bubbles have risen to the surface and burst, the pancake is ready to flip. Flip the cakes and cook until the bottom is golden brown.
Remove the pancakes from the grill to serving plates. Top with the macerated strawberry coulis and garnish with powdered sugar.