WW's 5 Ingredient Pineapple Updside-Down Cake

Not too long ago I had friends over for Tuesday Night Dessert instead of Tuesday Night Dinner.  I did this bcause 1) I'm broke right now, 2) I had ingredients to make desserts, and 3) my house needed a reason to be cleaned.  While going to recipes in my email I came across this one...  I love cake.  I love pineapple.  I love pineapple upside-down cake.  So why not try the "diet" version.  It was so good!  You'd never know it was a weight watcher's recipe.

Points Value:  3
Serves: 10
Prep Time:  7 minutes
Cooking Time:  40 minutes

Ingredients:
1/4 cup unsalted butter, divided
1/4 cup packed light brown sugar
3/4 pound canned pineapple slices (rings) in juice, reserve 1/4 cup juice
1/4 pound unprepared vanilla cake mix, about 1 scant cup
1 large egg

Instructions:

1. Preheat oven to 375F.
2. Melt 2 tbs butter in a 9" round, flameproof, aluminum pan over medium-low heat (make sure to cover entire pan bottom); sprinkle sugar over top.  Carefully place pineapple rings (use 7 rings) in a single layer in bottom of pan.  Increase heat to medium-high and cook until pineapple caramelizes, flipping once, about 2 minutes per side; remove pan from heat.
3. Melt remaining 2 tbs butter on stove top or microwave.  In a medium-sized mixing bowl, beat egg with remaining melted butter.  Add cake mix and reserved pineapple juice; combine well.
4. Pour batter over pineapple; bake until a toothpick inserted in center of cake comes out clean, about 30-35 minutes.  Allow cake to cool for about 15-20 minutes; when still warm, loosen sides with a knife and invert cake onto a serving plate.  Slice into 10 pieces and serve.  Yields 1 slice per serving.