Combine the strawberry slushie ingredients in a blender. Pulse for 15-30 seconds or until smooth. Check the sweetness and add more simple syrup as needed to your taste.
Pour the strawberry slushie into a pitcher and set it aside.
Clean out the blender and add in the mango slushie ingredients. Pulse for 15-30 seconds or until smooth. Check the sweetness and add more simple syrup as needed to your taste.
Alternate layers of strawberry and mango slushie in your cocktail glasses until they're full. Garnish this cocktail with a fresh strawberry on the rim. Serve immediately.
Notes
If you prefer to use fresh fruit, prep the strawberries by hulling them and slicing. Then peel and chop the mangoes. Place each type of fruit into Ziploc bags and freeze overnight. The frozen fruit lets you skip adding ice and makes these drinks taste better.