Easy Pineapple Upside-Down Cake

Folks-
By now you've realized that I use this site to keep the recipes I've tried and liked more than those that I've created myself. The reason I'm reposting all of these recipes is that I like them, and don't want to lose them either by an Internet company going under or abandonment, or simply by me forgetting that the recipe exists, or where it was located. This is one of those recipes I tried recently, and my wife loved it so much that I was afraid of losing it! I found it at food.com, a site I go to fairly frequently.
Soon I may post the fried chicken recipe I cobbled together that Zhenie loves. I hope to at least!
For today: Upside-Down Cake!

Ingredients:
1 (18 ounce) box yellow cake mix
3 eggs (or as called for by your cake mix)
1/3 cup oil (or as called for by your cake mix)
1 1/3 cups water (or as called for by your cake mix)
1 cup dark brown sugar
1/2 cup butter
1 (20 ounce) can sliced pineapple
1 (8 ounce) jar maraschino cherries (optional)
halved walnuts (optional)

Follow the instructions on the cake box for making an oblong single layer cake. Prepare the cake batter and set aside. Cut up the butter in small pieces and place all over the bottom of the oblong pan specified on the cake box. Sprinkle the brown sugar generously over the butter. Place pan on the stove (or in the oven) and heat slowly until butter and sugar melt to a liquid then remove from heat. Evenly space the pineapple slices around the bottom of the pan in the heated sugar and butter. Place the cherries and nuts between the pineapple slices (Though the cherries and nuts look nice and taste great, they are optional). Pour the cake batter on top of the pineapple/cherry/nut mixture. Place in the oven and bake as directed on the cake box. As soon as the cake is done place a plate over the cake and turn it upside down and carefully remove the pan. If you wait too long the sugar will harden and be difficult to remove. Note: Peaches may be used in place of pineapple.