Okay, I found the cake mix one. The recipe tells you to use a cake pan, but I see no reason why you can't adapt it to use a large skillet.
The other homemade cake recipe is from a cookbook, so I'll send it to you via PM.
Enjoy! Here it is:
PINEAPPLE UPSIDE-DOWN CAKE
1 (2-layer) pkg. pineapple-flavored cake mix OR
yellow cake mix
½ cup butter or margarine
1 cup firmly packed brown sugar
1 (20-oz.) can pineapple slices, drained (reserve juice)
Large red maraschino cherries
Pecan halves, optional
Melt butter in a ungreased 13- x 9- x 2-inch baking dish. Sprinkle brown sugar evenly in pan. Arrange pineapple slices on brown sugar. Place maraschino cherries in center of pineapple slices. Fill in spaces between pineapple rings with pecan halves.
Prepare cake mix according to package directions for basic recipe, substituting most or all of the water with pineapple juice.
Pour batter evenly over fruit in pan. Bake in preheated 350º oven for 43 to 48 minutes or until toothpick inserted in center comes out clean. Cool 5 minutes in pan before inverting onto serving plate.