Heat oven to 375ยบ. Mix baking mix, milk, sugar and margarine until soft dough forms. Spread in ungreased 9x9 square pan. Arrange peach slices on top. Mix sugar and cinnamon and sprinkle over peach slices. Mix sour cream and eggs. Drizzle over top. Bake until wooden pick inserted in cake comes out clean (35-40 minutes). Serve warm with whipped cream.