1. Prepare the Cake Layers:

1. Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

2. In a bowl, cream together the softened butter and sugar until light and fluffy.

3. Add the egg and vanilla extract, beating well.

4. In a separate bowl, whisk together the flour, baking powder, and salt.

5. Gradually add the dry ingredients to the wet mixture, alternating with milk, beginning and ending with the dry ingredients. Mix until smooth.

6. Drop tablespoons of batter onto the baking sheet to form small, round cakes about 2 inches in diameter. Flatten slightly with the back of a spoon.

7. Bake for 8–10 minutes or until the cakes are lightly golden and spring back when touched. Let cool completely.

2. Make the Marshmallow Filling:

1. In a bowl, mix the marshmallow fluff, softened butter, and vanilla extract until smooth and creamy.

3. Assemble the Pies:

1. Pair up the cooled cake rounds by size.

2. Spread about 1 tablespoon of marshmallow filling on the flat side of one cake, then sandwich with the matching cake on top. Press gently to seal.

4. Coat with Chocolate:

1. Melt the chocolate and oil together in a microwave-safe bowl or over a double boiler until smooth.

2. Dip each marshmallow sandwich into the melted chocolate, ensuring it’s fully coated. Use a fork to lift and let excess drip off.

3. Place the coated pies on a parchment-lined tray. Refrigerate until the chocolate sets, about 30 minutes.