Whisk together the egg, water, flour, baking powder, salt, and agave until smooth.
Heat the peanut oil over medium-high heat until a piece of bread dipped in sizzles.
Stick marshmallows on the end of the skewers and spread about 1 teaspoon of peanut butter around the outside for each skewer. Dip the whole marshmallow in the batter and make sure all sides and edges are covered completely.
Hold the stick and place in the hot oil turning slowly but constantly until all sides are a nice medium-brown color. Place on paper towels to cool and enjoy!