Whisk the gluten-free flour, sugar, baking powder, baking soda, and salt in a bowl.
Whisk the milk, egg, melted butter, and vanilla in a separate bowl until smooth.
Pour the wet ingredients into the dry ingredients.
Stir gently until the batter comes together with small lumps.
Heat a nonstick pan over medium heat.
Add a thin layer of butter or oil to the pan.
Scoop ¼ cup of batter into the pan for each pancake.
Cook until bubbles form around the edges.
Lift the edge with a spatula to check for a golden bottom.
Flip the pancake when the edges look set.
Cook the second side until lightly golden and springy.
Transfer the cooked pancake to a plate.
Repeat with the remaining batter.
Serve warm with berries and maple syrup.