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.