Freeze the Marshmallows:
Place the marshmallows in the freezer for at least 30 minutes before starting. This helps them hold their shape during frying.

Prepare the Batter:
In a mixing bowl, whisk together the whole milk, egg, and vanilla extract until smooth. Gradually add the buttermilk pancake mix, stirring until just combined. The batter should be slightly thicker than regular pancake batter but still pourable.

Heat the Oil:
Pour canola oil into a deep pot, filling it to a depth of 3–4 inches. Heat the oil to 375°F. Use a kitchen thermometer to maintain the correct temperature.

Coat the Marshmallows:
Working in small batches, dip the frozen marshmallows into the batter, ensuring they are fully coated. Let any excess batter drip off.

Fry the Marshmallows:
Carefully lower the coated marshmallows into the hot oil using a slotted spoon. Fry for about 30 seconds per side, or until golden brown. Be attentive, as they cook quickly.

Drain and Serve:
Remove the fried marshmallows from the oil and place them on a paper towel-lined plate to drain excess oil. While still warm, dust with powdered sugar or drizzle with chocolate syrup and add sprinkles, if desired. Serve immediately for the best taste and texture.