Combine corn meal, flour and salt in a mixing bowl.
In a separate bowl, combine buttermilk, milk and egg. Add baking powder and baking soda to the wet ingredients. Stir into the dry ingredients. Add melted butter, slightly cooled, stirring constantly.
Fill the prepared pan a little more than half full with batter. Cut a hot dog into pieces, small rounds if using mini muffin tins; 1-inch slices if using larger muffin tins.
Bake until cornbread is done, about 10-12 minutes.
Remove from the pan. Serve with ketchup and mustard.