Upside-Down Caramel Banana Cake

I can't remember where I got this recipe from, therefore I can't give credits... But it's a great recipe and very useful if you have any over riped bananas laying around.

Ingredients:

Batter:
1 Mashed Banana
Sour cream 3 TB
Flour
Cinnamon 1/2 t.s.
Nutmeg 1/8 t.s.
Butter 6 TB (room temperature)
Sugar  Just under 1 cup
Vanilla Extract 1 t.s
2 Eggs

Caramel Topping:
Butter 4 TB
Brown Sugar 3/4 cup, lightly packed
Maple Syrup 2 TB
3-4 sliced bananas

Instructions:
Grease a 23 cm round or square pan.

Topping:
Melt butter in a saucepan over low heat, add brown sugar and syrup. Remove from heat once it starts to bubble. Pour sauce into the pan. Arrange sliced bananas over the sauce.

Batter:
In a small bowl combine mashed banana and sour cream, mix well. In a separate medium bowl, sift together flour and spices. Set aside.
Beat butter and sugar with an electric mixer until fluffy. Add vanilla and 1 egg. Mix. Add the second egg. Mix again. Add the flour mixture to the butter mixture and beat. Add sour cream and banana mixture and mix with a wooden spoon until just combined.
Spread into pan. Bake about 40-45 minutes, or when a toothpick comes out clean when inserted in the middle. Serve with a dollop of whipped cream.