Ingredients are as follows:
cake batter:
1 C brown sugar
1 C sour cream
1/2 C butter, softened
2 eggs
3 medium ripe bananas
1 tsp. vanilla
2 C flour
1 tsp. baking soda
1/4 tsp. salt
1 C toffee bits (from an 8 ounce bag)
frosting:
1/2 C butter
3 C powdered sugar
1 tsp. vanilla
1/2 C milk
remaining toffee bits
Directions:
Preheat oven to 350 degrees; grease a 9 x 13" pan.
Start with the frosting:
Melt the 1/2 C butter over medium heat until it turns brown. This takes about 4-6 minutes. Watch carefully because once it's starts, it happens quickly. Remove from heat and set aside to cool.
Now for the cake: cream together the brown sugar, sour cream, and butter.
Mix in the eggs, bananas and vanilla.
By hand, stir in the flour, baking soda, salt and 1 C toffee bits.
Pour into prepared pan. Bake for 30-35 minutes; until golden brown.
Remove from the oven and poke some holes throughout the cake; set aside.
Pour the browned butter into a bowl; mix in the powdered sugar and vanilla.
Whip in the milk until it becomes creamy and fluffy.
Immediately spread over the warm cake.
This will melt into the cake and ooze down into the holes.
Sprinkle the remaining toffee bits on top.
Slice, serve and enjoy! source