Preheat oven to 400 degrees. Spray a 12-cup muffin pan with nonstick spray.
In a large bowl, mix all dry ingredients.
In a medium bowl, whisk together butter, milk and egg. Pour into dry ingredients. Stir until just combined.
Stir in green onions, 1 cup cheddar and ½ cup Pecorino Romano cheese. Reserve the remaining cheese for top of muffins.
Divide batter between muffin cups. I actually got 10 muffins so it depends on the size of your pan. Sprinkle tops with cheese.
Bake in oven for 17-20 minutes or until tops just start to brown. Remove from oven, run a silicone spatula around the outside to loosen any melted cheese then remove from pan and place on wire rack to cool. Or eat them right away as you’ll find them impossible to resist!