Classic Whoopie Pie Recipe

Preheat oven to 180 °C (350°F) conventional (see note 1 if using a convection with a fan) and line three baking sheets with parchment paper (I use two half sheet baking trays and one smaller tray). Set aside for now.

In a bowl sift together all purpose flour, cocoa powder, baking powder, baking soda and salt. Using a whisk, mix until well combined and set aside for now.

In a large bowl add in light brown sugar, oil, egg, vanilla and instant coffee powder. Using a whisk, mix until well combined and smooth.

Add dry ingredients to the wet ingredients and using a spatula, fold until just combined. The batter will be very thick (like a cookie dough), so you will need to gently push the dry ingredients into the wet ingredients.

Add the hot milk to the batter, and fold until well combined and smooth. You should end up with a thick cake batter like consistency.

Using a medium sized spring loaded cookie scoop (holds 1½ tbsp of batter), portion out the batter 2 inches apart on the prepared baking sheets - don't worry if they're not completely round. You can pipe the batter out too or scoop out heaped tablespoons full. Once all the batter is portioned (you should have about 30 cookies), lightly dip your fingers in some oil and use your fingers to gently shape the edges of the cookies so they're round.

Bake one tray at a time in the middle rack of the oven for 10 minutes, or until the tops are somewhat firm and set and spring back when you touch them.

Allow the cookies to cool on the tray for 15 minutes, before carefully peeling them off the parchment paper and then allow them to fully cool on the tray. In the meantime prepare the frosting.

In a large bowl add in butter and powdered sugar and using a hand or stand mixer on a medium-high speed, whip until light and fluffy.

Add in marshmallow fluff and vanilla and mix until smooth. Avoid over-mixing.

Place half of the cookies upside down and using the same medium spring loaded cookie scoop used for the batter, place dollops of the buttercream on the flat edges of the cookies (you can use a piping bag to pipe the buttercream on too). Place the remaining cookies on top (flat side on the buttercream) and squeeze gently until the buttercream spreads to the edges. Enjoy!