Blend espresso, instant coffee, milk, ice, and homemade Frappuccino base syrup until smooth.Start the blender on low, then turn it up to high. Use a tamper tool to make sure the ice gets blended evenly.
Frappuccino base syrup is the secret ingredient that turns a frozen, slushy drink into a Frappuccino. This recipe is made with a homemade Frappuccino base syrup to give it that same texture.
If you don't want to use the base, you can just use simple syrup but it won't have the same Frappuccino texture.
Don't add ice first into a blender since it'll be harder to get an efficient blend. Add ingredients as instructed in the recipe.