Heat oven to 350 degrees. Line a 8x8 inch pan with foil and spray with a non-stick spray. Melt margarine and chocolate in a medium saucepan over a low heat, stirring often. Remove from heat and whisk in sugar and remaining ingredients, except the peppermint patties. Pour half of the batter into the lined baking dish. Then sprinkle cut up peppermint patties over top of batter. Add remaining batter and bake for 25 to 30 minutes. Cool and frost with your favorite frosting, then enjoy!