Whisk together 1 cup buckwheat flour, 1 teaspoon baking powder, 1/2 teaspoon baking soda, and 1/4 teaspoon salt in a bowl.
Whisk the egg, buttermilk, melted butter, sugar, and vanilla extract in a separate bowl.
Pour the wet ingredients into the dry ingredients and stir until smooth. Let the batter rest for 5 minutes.
Preheat a non-stick skillet over medium heat and lightly grease with butter or oil.
Pour 1/4 cup of batter onto the pan for each pancake. Cook for 2–3 minutes until bubbles form, then flip and cook for another 1–2 minutes until golden brown.
Serve warm with maple syrup, butter, fruits, or yogurt.