Butternut-Pecan Muffins with Brown Sugar Crumble - Rick Bayless

Ingredients

• 1/2 small (2 pound) butternut squash, peeled, seeded and cut into 1-inch chunks (about 3 cups of chunks)
• 1/3 cup brown sugar
• 3/4 cup toasted pecan pieces, divided use
• 2 tablespoons sour cream
• 1 1/2 teaspoons vanilla, preferably Mexican
• 2 eggs
• 1 1/2 cups cake flour
• 3/4 cup granulated sugar
• 1 teaspoon ground cinnamon, preferably Mexican canela
• 1 teaspoon baking soda
• 3/4 teaspoon baking powder
• 1/2 teaspoon salt
• 5 ounces (10 tablespoons) unsalted butter, softened