This Blueberry Frosting is perfect for cakes, cupcakes, cookies, and more! The bright blueberry flavor and color (without a drop of food dye) are irresistible!
Combine blueberries, sugar, and lemon juice in a saucepan. Cook over medium-low heat, stirring occasionally, until the blueberries break down and give off their juice, about 5 minutes.
Strain the blueberries through a fine mesh strainer, discarding the skins/seeds. Pour the blueberry juice back into the saucepan and simmer over medium-low heat until reduced by half, about 5-10 minutes. (I started off with 1 cup of blueberry juice, and reduced it to ½ cup). Make sure to stir it often as it cooks so that it doesn't stick to the pan or scorch as it thickens. Allow the blueberry reduction to cool to room temperature.
Cream butter and powdered sugar in the bowl of a stand mixer until smooth. Gradually add the blueberry reduction (should be about ½ cup) and mix to incorporate.
If not using the frosting immediately, place it in an airtight container and it will keep in the refrigerator for up to a week. You'll have to take the frosting out of the fridge to warm up for it to be a spreadable/pipeable consistency. If necessary, the frosting can be re-whipped to a smooth consistency.Enjoy!