Justine recommends enlisting help from a stand or hand mixer to break up the blueberries and fully incorporate them into the rest of the wet ingredients. This mixing will also help aerate the butter in your cookies, which gives them an even lighter, fluffier texture (the higher the speed, the better). “This cookie dough will be very soft and slack compared to other doughs, and that’s totally normal! Don’t panic. Just because of the higher moisture content from the berries,” says Justine. “But a loose dough can be tricky to handle, so I recommend chilling the dough for about 30 minutes before scooping it into cookie dough balls.”
