Preheat oven to 350 degrees F (175 degrees C). Grease and flour 4 muffin cups or ramekins.
Sift cornmeal, tapioca flour, rice flour, buckwheat flour, baking powder, baking soda, and salt into a large bowl. Add butter to cornmeal mixture and stir until well combined. Mix milk, eggs, honey, and vinegar into cornmeal mixture just until batter is combined, adding more cornmeal if batter is too runny. Pour batter into the prepared muffin tins.
Bake in the preheated oven until tops are firm and lightly browned, 20 to 25 minutes; cool in the muffin cups for 3 minutes before transferring to a wire rack to cool completely.