In a bowl, mix the flour, sugar, baking powder, and baking soda together and then add the water and vinegar (combined first) and continue stirring until a dough forms.
Turn the dough out onto a floured surface. Knead for 2-3 minutes. form into a small loaf 1 to 1.5 inches tall. Cut an X (or your preferred shape) into the top of your loaf and place onto your pizza stone.
Cook in the oven and bake for 30-40 minutes or until the crust has browned.
Remove the bread and brush with melted butter while it is still hot.
Notes
This recipe doesn't call for salt. You may want to add some for flavor. You could also add in some herbs if you'd like.