In a large mixing bowl, combine almond flour, baking powder, erythritol, lemon zest, and salt, Whisk to combine. Set aside.
In a medium mixing bowl, add three egg yolks, vanilla, lemon juice, almond milk, and ricotta cheese. Whisk vigorously to combine ingredients. Add wet ingredients into dry and mix with a wooden spoon until just combined to form a batter. Batter will be slightly thicker at this point, but add additional almond milk 1 tablespoon at a time if the batter looks too much like a cake batter.
In a clean mixing bowl, add the egg whites. Using a mixer beat on high power until stiff peaks form. Add the whipped egg whites into the batter by hand, mixing in slowly with a wooden spoon until just combined. Do not overmix. Batter should be a pourable consistency at this point.
Heat a large non-stick skillet over medium-low heat and grease lightly with a neutral-tasting oil. Pour about 2 to 3 tablespoons of batter for each pancake; smaller pancakes will be easier to work with. Cook for 2-4 minutes until the edges and bottom are set. Drop a few blueberries on top and carefully flip. Continue to cook for another 2-4 minutes on the other side until both sides are a golden brown. Remove to a large serving plate and repeat until all batter is gone.
Top with additional berries, butter, sugar-free maple syrup, or cream. Serve immediately.