Spray oil on sides and bottom of a 9x9 baking pan. For extra easy clean up, cut a piece of parchment paper to fit the bottom of the pan, too.
Preheat oven to 400 degrees F.
Mix together in a large bowl, Bisquick, cornmeal, sugar, and baking powder.
In a smaller bowl, mix egg, milk, and oil.
Add wet ingredients to dry ingredients and mix just enough to blend and get out any lumps.
Pour batter into baking pan.
Bake at 400 degrees F for 30 minutes. Let cool 5 minutes. Serve warm, with or without butter.