Brown Butter Pumpkin Cupcakes

Ingredients

• 3/4 cup unsalted butter
• 2 cups all-purpose flour
• 1 1/2 tsp. baking soda
• 3 tsp. ground cinnamon
• 1 tsp. ground ginger
• 1 tsp. salt
• 1/4 tsp. allspice
• 1 1/2 cups granulated sugar
• 1/2 cup firmly packed light brown sugar
• 1 1/2 cups pumpkin puree
• 3 large eggs
• 1/2 cup sour cream
• 1 lb. (4 sticks) unsalted butter, room temperature
• 1 cup brown sugar
• 8 cups confectioners’ sugar
• Milk or cream to thin
• 2 Tbs. molasses
• Pumpkin spice and freshly grated nutmeg for garnish, optional