Pour oil into pot being used for frying, at least one inch deep. Heat to medium-high heat.
In a glass bowl, mix egg, milk and bisquick mix with a large wooden spoon or whisk. Let small lumps remain in batter.
Dip thin mint until covered in batter on both sides. Grab very small edge of the thin mint to remove and quickly put into the hot frying oil before the batter drips off. Fry for about 15-20 seconds before turning over to other side. Fry other side so both are evenly brown. Remove and place on plate lined with paper towel. Repeat with remaining thin mints. Dust with powdered sugar before serving.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.