Ebekskivers (Recipe from Serious Eats)--if making into pancakes, you may need a little more milk, but use the same method.
In a large bowl, whisk together egg yolks, milk, and 2 tablespoons melted butter until combined. Stir in dry ingredients. Mixture should be lumpy—do not overmix.
In a small bowl, beat egg whites with an electric mixer or whisk until stiff but not dry peaks form, about 3 minutes. Fold egg whites into batter.
Put ebelskiver pan over medium high heat. Spray mold heavily with non-stick cooking spray. To each mold, add 1 tablespoon of batter. Top each well with 1 teaspoon of jam, then top with another 1 tablespoon batter. Let ebelskivers cook until bottoms are golden, about 4 minutes, then flip and continue to cook until tops are also golden, 3 minutes more. Transfer to a plate and tent with foil. Repeat with rest of batter, then serve immediately with powdered sugar on top.
If you don't want to fill the pancakes while they are cooking, just cook them with only batter and then cut in half after they are cooked.
For the ricotta filling, mix the ingredients together until smooth. Spoon a teaspoon of this batter into the center of the pancake, along with a spoonful of berry jam (black berry, marion berry, etc.). Put the 'lid' on and serve with a sprinkling of powdered sugar and/or maple syrup.