Stir together flour, sugar, salt & yeast in mixing bowl. Add butter and about 1 1/2 cup of milk until ingredients form a ball. If dough is too stiff, add more milk.
Knead the dough using the sough hook for about 10 minutes. Dough should be tacky, not sticky and should pass the windowpane test. Coat ball with oil and place in bowl, cover with plastic wrap.
Ferment at room temperature until dough doubles in size (about 60-90 minutes).
Divide dough in 12 equal pieces (about 3 oz each) and shape each into a boules. Line a sheet pan with parchment, mist with spray oil and dust with cornmeal. Place boules on sheet about 3 inches apart (I use 2 sheet pans with 6 boules on each). Spray tops with oil, dust with cornmeal and cover with plastic wrap.
Proof at room temperature for 60-90 minutes or until pieces are close to double in size.
Heat a skillet and preheat oven to 350˚F.
Mist skillet with spray oil and place muffins gently on pan so that they are at least 1 inch apart and not touching. Cook for 5 – 8 minutes on one side and then flip and repeat on other side. Transfer pieces back to sheet pan and bake in oven for 5 minutes to ensure the center is baked.
Transfer cooked muffins to a cooling rack and allow to cool for at least 30 minutes before slicing or serving.