Bring 1 cup berries and 1 teaspoon sugar to simmer in small saucepan. Cook, mashing and stirring berries frequently, until berries have broken down, mixture is thickened and reduced to ¼ cup, about 6 minutes. Cool to room temperature, 10 to 15 minutes.
Adapted slightly from America’s Test Kitchen.
You can use frozen or fresh blueberries, or a mixture of the two. If using frozen berries for compote, no need to thaw. If using frozen berries for folding into muffins, make sure you thaw and drain the extra liquid so that the muffins don’t get gummy.