In a separate large bowl whisk together the oil, sugars, vanilla extract and eggs. Then stir in the sour cream and pumpkin puree.
1/2 Cup Vegetable Oil, 3/4 Cup Brown Sugar, 1/4 Cup Sugar, 2 teaspoons Vanilla Extract, 2 Large Eggs, 1/4 Cup Sour Cream, 1 ½ Cups Pure Pumpkin Puree
Fold in the dry ingredients and the chocolate.
3/4 Cup White Chocolate Bar
Spoon the batter into the prepared muffin pan, filling each to the very top.
Bake at 425℉ for 5 minutes. Then without taking the muffins out of the oven, turn the temperature down to 350F and continue baking for 15-17 minutes or until an inserted toothpick comes out clean.
Allow to cool in the pan for 5 minutes, then continue cooling on a wire rack.
Notes
May be kept for 2-3 days at room temperature, or frozen for up to 3 months.