Banana Bread Brownies - Eat it or go Hungry

Ingredients

• For the banana bread brownies:
• 1 ½ cups sugar;
• 1 cup sour cream;
• ½ cup (1 stick) unsalted butter, at room temperature;
• 2 eggs, at room temperature;
• 3 bananas, mashed;
• 2 tsp vanilla extract;
• 2 cups all-purpose flour;
• 1 tsp baking soda;
• ¾ tsp salt;
• ½ cup walnuts, chopped.
• For the frosting:
• ½ cup unsalted butter;
• 3 cups powdered sugar;
• 1 ½ tsp vanilla extract;
• 3 tbsp milk.