In a large bowl, combine the pancake mix with cold water. Let the batter sit for 5 minutes. This helps the dry ingredients absorb the liquid, resulting in a consistent batter that yields great pancakes from start to finish.
Add the blueberries to the batter and gently fold them into the batter.
Cook the pancakes:
Heat a large non-stick pan or griddle over medium heat. Once hot, grease it with oil, butter, or spray. Immediately pour ¼ cup of batter per pancake, ensuring that there's an even amount of blueberries in each. Cook the first side for approximately 2 minutes, then flip the pancakes over and cook the other side for an additional minute or two. Avoid pressing down with the spatula.
Remove the pancakes from the pan and serve them immediately, or keep them warm while you repeat the process with the remaining batter.
Store:
Refrigerate unused batter, covered, for up to 2 days. Let it come to room temperature on the counter before cooking. Cold batter is thick and difficult to pour. Store leftover cooked pancakes in the fridge in an airtight container for up to 3 days, or freeze them for up to 3 months.