
Preheat oven to 350F.
Blend together the cake mix, eggs, oil, and nectar and food coloring, if using, until well combined. Fold in the peaches and turn the batter into a lightly sprayed 9x12 pan. Bake for about 28 minutes, or until done.
Put the butter, cream, and brown sugar in a saucepan and bring to a boil, stirring constantly. Take off the heat and add the vanilla and the sifted sugar. Whisk until well blended.
Pour the frosting over the cake, trying to get it evenly coated on the first try, because it will set up quickly.
Let the frosting harden at room temperature or in the refrigerator before cutting.