Combine milk and eggs in a blender; pulse until well mixed. Add flour, cocoa powder, sugar, baking powder and salt; pulse until pancake batter is well blended. Add water 1 tablespoon at a time if batter appears too thick.
Heat a lightly oiled non-stick pan over medium-high heat. Drop a ladle of batter onto the pan and cook until bubbles form and the edges are dry, 2 to 3 minutes. Flip and cook until browned on the other side, 2 to 3 minutes. Repeat with remaining batter until you have at least 6 pancakes. Transfer pancakes to a wire rack to cool.
Mix cherry puree and vodka together in a bowl.
Brush 1 pancake with cherry puree mixture and pipe whipped cream on the edge of the pancake; top with another pancake. Repeat until all the pancakes, cherry puree mixture and whipped cream are used. Top with sweet cherries and chocolate shavings. Slice cake using a serrated knife.