I used a scoop (a #16 disher) to put the batter into the muffin pan. The muffins baked at 400ºF, and for us they took 20 minutes. We let them cool in the pan for about 5 minutes, then put them on a rack and let them cool just a bit longer before digging in.
Chocolate Chip Pumpkin Muffins
(adapted from Dorie Greenspan's Baking From My Home to Yours)
1 cup (135 grams) all-purpose flour
1 cup (135 grams) white whole wheat flour
2 teaspoons baking powder
1/4 teaspoon baking soda
1/2 teaspoon table salt
3/4 teaspoon ground cinnamon
1/2 teaspoon ground ginger
1/4 teaspoon freshly grated nutmeg
8 tablespoons (1 stick/115 grams) unsalted butter
1/2 cup (100 grams) granulated sugar
1/4 cup (50 grams) light brown sugar
1/2 teaspoon vanilla extract
2 large eggs, at room temperature
3/4 cup (170 grams) canned pumpkin puree (not pumpkin pie filling!)
1/3 cup (75 grams) plain yogurt
1 cup (170 grams) chocolate chips (or nuts or dried fruit--any mix you like)
Make sure your rack is in the center of the oven and preheat the oven to 400ºF. Line a standard 12-cup muffin pan with paper muffin cups (I use grease-proof ones like these) or spray the molds with baking spray.
In a medium bowl, whisk together the flours, baking powder, baking soda, salt and spices. Set aside.
Using a stand mixer fitted with the paddle attachment or with a hand mixer in a large bowl, beat the butter until soft. Add the sugars and beat until light and smooth, then mix in the vanilla. Next, beat in the eggs one at a time. Continue to beat the mixture for about a minute after the eggs are in, then mix in the pumpkin and yogurt. Stop the mixer and scrape down the sides of the bowl. Then, with the mixer on low, gradually add the dry ingredients, mixing only until they disappear. Remove the bowl from the mixer, and fold in the chocolate chips with a spatula, making sure that all the ingredients are completely blended. (I find that some of the butter/sugar mixture sits in the bottom of the bowl and doesn't get thoroughly mixed in with the paddle.)
Divide the batter between the prepared muffin cups. Bake the muffins for 20-25 minutes, or until a toothpick inserted in the center comes out clean and the tops of the muffins are lightly browned. Allow the muffins to cool in the pan for 5 minutes, then remove them from the pan and put them on a rack to finish cooling.