In a small bowl, stir together the flour, sugar, baking powder, nutmeg, salt in a small bowl. In a larger bowl, whisk together the ricotta, eggs, milk, lemon juice and zest. Add the flour mixture and stir just until combined.
Preheat a heavy skillet (cast iron is ideal) or griddle and brush with oil and/or butter. Turn it down to medium-low and ladle on some batter (about 1/3 cup, depending how big you want them). Cook until golden on the bottom and bubbly on the top, with some bubbles breaking through; flip with a thin spatula and cook until golden on the other side. Keep them warm in a 250F oven if you like.
Meanwhile, roughly mash the berries with the sugar in a small saucepan over medium heat and bring to a simmer. As soon as the sugar dissolves, it's ready to serve. If you want it runnier, add pure maple syrup for a pourable blackberry sauce.