Peel your bananas, place them in a Ziploc bag and freeze overnight.
Juice your oranges. You can do this using a fancy juicer, citrus press, or by hand. (Relax, you’ll only need to juice 3 at most.)
Place the frozen bananas, orange zest, orange juice, almond milk, vanilla extract, and ice in a blender or food processor and puree until smooth. (Add agave to sweeten if necessary.)
Pour into two glasses and garnish with orange slices if you’re feeling fancy.