Vegetable oil or cooking spray for the pan or paper muffin liners.
3-1/2 cups all-purpose flour
4 tsp. baking powder
1/2 tsp. baking soda
1/2 tsp. table salt
1-1/3 cups granulated sugar
3/4 cup canola or vegetable oil
1 cup milk,any percent you have at room temperature
1 cup sour cream or plain yogurt, at room temperature
2 large eggs, at room temperature
1 large egg yolk, at room temperature
2 tsp. finely grated lemon zest
1-1/2 cups fresh (washed, dried, and picked over) or frozen (no need to thaw) blueberries
1 cup cranberries fresh or frozen ( no need to thaw)
Overfilling the muffin cups gives you those great big bakery-style muffin tops.
Position a rack in the center of the oven and heat the oven to 350°F. Lightly oil (or spray with cooking spray) the top of a standard 12-cup muffin tin and then line with paper or foil baking cups. (Spraying the pan keeps the muffin tops from sticking to the pan’s surface.)
In a large bowl, sift together the flour, baking powder, baking soda, and salt; mix well. In a medium bowl, whisk the sugar, oil, milk, sour cream ( or yogurt), eggs, egg yolk, and zest until well combined.
Pour the wet ingredients into the dry and fold gently with a rubber spatula just until the dry ingredients are mostly moistened; the batter will be lumpy, and there should still be quite a few streaks of dry flour. Sprinkle the berries on the batter and fold them in until just combined. (The batter will still be lumpy; don’t try to smooth it out or you’ll over mix which makes for a tuff muffin )
fill the muffin cups, I used a 1/2 cup measuring cup, Otherwise, use two spoons to spoon the batter in, distributing all of the batter evenly. I had a little batter left over and made 8 mini muffins.
Bake until the muffins are golden brown and spring back lightly when you press the middle, 30 minutes. Let the muffin tin cool on a rack for 15 to 20 minutes.