These muffins are simply wonderful. They have a great muffiny crumb rather than tasting like cupcakes with blueberries added. And they are not hard to make at all. I used frozen blueberries because that is what I had on hand. I also made a couple other alterations, the original recipe has a lemon sugar topping and I left that out because I'm not a fan of crunchy sugar on my muffins (personal preference). The recipe makes 12 muffins.
America's Test Kitchen Best Blueberry Muffins
2 cups frozen blueberries, divided (can use fresh of course)
1 1/8 cups sugar (8 oz) + 1 teaspoons sugar, divided
2 1/2 cups flour
2 1/2 teaspoons baking powder
1 teaspoon salt
4 tablespoons butter, melted and cooled slightly
1/4 cup oil (I used a canola oil blend)
1 cup buttermilk (I used 1 T. vinegar + enough milk to equal 1 cup)
1 1/2 teaspoons vanilla
Preheat oven to 425 and spray a standard muffin tin with non-stick cooking spray.
Bring 1 cup of blueberries and 1 teaspoon of sugar to a simmer in a small pan over medium heat. Cook, mashing berries with a spoon several times and stirring frequently, until berries have broken down and mixture is thickened and reduced to about 1/4 a cup - about 6 minutes. Transfer to a small bowl and cool to room temperature for 15 minutes.
Rinse the remaining cup of frozen blueberries under water and then dry the berries with paper towels and allow them to sit on a layer of paper towels.
In a large bowl whisk together flour, baking powder, and salt.
In a separate bowl whisk together 1 1/8 cups sugar (that's 1 cup + 2 tablespoons sugar) and eggs until thick and creamy - about 45 seconds of good whisking. Slowly whisk in butter and oil until combined. Whisk in buttermilk and vanilla until combined.
Put the 1 cup of whole dried blueberries into the flour mixture and toss to coat them well with the flour. With a rubber spatula gently add the wet mixture to the flour mixture folding until just moistened with a few small spots of dry flour (you don't want to overmix).
Scoop muffin batter evenly into muffin tin cups - a ice cream scoop works great. Muffin tins should be almost full to the top. Take 1 teaspoon of the cooked and cooled blueberry compote and place in the center of each muffin cup of batter. Take a skewer and gently swirl the compote into the batter in a figure 8 motion. Bake for 16 - 19 minutes, rotating muffin tin halfway through baking to ensure even baking. Finished muffins should be golden and just firm. Cool muffins in the muffin tins for 5 minutes. Then transfer to wire racks and cool 5 minutes before serving.