If you are using frozen berries, you can use them frozen, just separate them so they’re not sticking together and toss them in flour to coat. Your cooking time may need to increase by a few minutes.
Some brands of sour cream are much thicker than others. Feel free to dilute the sour cream with a little water if you think it’s too thick. You can also substitute the sour cream with plain yogurt; if you do, you likely will not need both tablespoons of added milk.
1 Preheat the oven and prep the muffin tin: Preheat your oven to 400°F with a rack in the lower middle. Using a standard 12-well muffin pan, place a muffin liner in each well, or if you don’t have muffin liners, grease the inside of the muffin pan wells with vegetable oil or butter.
2 Toss the berries with flour: Place the…