Pour the mixture into the prepared white ceramic casserole dish and spread it into an even layer, smoothing the top with the back of a spoon or spatula. You should see a creamy pale yellow base dotted with blueberries.
Cover the dish tightly with plastic wrap or a lid to prevent freezer burn. Place it on a flat surface in the freezer and freeze for at least 4 hours, or until firm all the way through. For the best texture, freeze overnight.
When you’re ready to serve, remove the dish from the freezer and let it sit on the counter for 5–10 minutes to soften slightly. Scoop into bowls or cut into squares, making sure each serving has plenty of blueberries.
Return any leftovers to the freezer, tightly covered. This freezer salad keeps well for up to 1 week, making it a handy make-ahead “something fruity” to pull out after dinner on busy nights.
To make this a little more indulgent, you can sprinkle crushed graham crackers or shortbread cookies over the bottom of the greased dish before adding the mixture for a soft, crumbly base. If you like more texture, fold in 1/2 cup of mini marshmallows or chopped pecans along with the blueberries. For a slightly lighter version, use light lemon yogurt and light whipped topping; it will still freeze nicely, just with a softer texture. You can also swap in vanilla yogurt and add 1–2 tablespoons of lemon juice if you can’t find lemon yogurt. If your family prefers different fruit, try frozen raspberries, strawberries, or a mixed berry blend instead of blueberries—just keep the total amount the same. For easy weeknight portions, freeze the mixture in individual ramekins or a muffin tin lined with paper liners so you can grab single servings straight from the freezer without dirtying extra dishes.
