This frozen strawberry piña colada is super fresh and fruity with just the right amount of sweetness for a cocktail. Use a pineapple-flavored rum that uses 100% juice to avoid excess added sugars like we do here. You can use store-bought frozen pineapple, or if you have a perfectly ripe fresh pineapple on your hands, you can cut and freeze it instead (reserve a few fresh spears for garnish). To freeze pineapple, peel off the skin with a sharp knife and slice the fruit into 1-inch chunks. Freeze in a single layer on a small baking sheet or large plate to prevent the pieces from sticking together.