In a bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
In another bowl, whisk the buttermilk, egg, melted butter, and vanilla until smooth.
Pour the wet ingredients into the dry and stir gently until just combined.
A few small lumps are fine. Let the batter rest for 5 minutes.
Heat a nonstick skillet or griddle over medium heat. Lightly grease with butter.
Use a tablespoon to drop small pools of batter, about 1.5 to 2 inches wide.
Cook until bubbles form and edges look set, about 1 to 2 minutes. Flip and cook another 30 to 60 seconds until golden.
Transfer pancakes to a plate and keep warm. Repeat with remaining batter, adding a little butter to the pan as needed.
Assemble the stacks: place 3 mini pancakes on top of each other.
Add a berry between layers if you like. Secure with a toothpick or mini skewer.
Warm the maple syrup in a small saucepan or microwave-safe cup. Serve each person a small dipping cup of syrup.
Optional: Dust stacks with powdered sugar and scatter berries on the platter for a bright finish.