Whisk flour, cocoa powder, sugar, and salt together in a large bowl. Beat eggs, milk, and vanilla in another bowl; mix in the melted butter. Pour the wet ingredients into the dry, and mix just until combined. Stir in the chocolate chips.
Heat a lightly oiled griddle or skillet over medium-high heat. For each pancake, pour 1/4 cup batter on griddle and cook until bubbles pop in the center of the pancake, about 2 to 3 minutes. Flip, and cook an additional minute on the opposite side.
