Instructions

Make the Brownie Base

1. Preheat your oven to 350°F and prepare an 8x8" baking pan with non-stick spray. Line your pan with parchment paper by cutting one long strip for the bottom and two sides - fold over and trim the excess paper to edge of pan. Bring your eggs to room temperature by placing them in a glass of warm water for around 10 minutes.
2. Meanwhile, in a microwave-safe bowl, melt together the oil and chocolate chips, stirring the mixture every 15 seconds until chips are melted. Stir in the instant coffee and cocoa powder; set aside.
3. In the bowl of a stand mixer fitted with the whisk attachment, add the eggs and sugar. Whisk on medium-high speed until thick and light in color. Whisk in the peppermint and vanilla extracts. Gently fold the chocolate mixture into the sugar and eggs. Add the salt and cornstarch and gently mix until just combined.
4. Pour batter into prepared baking dish and bake at 350°F for 17-23 minutes or until a toothpick inserted into the brownies comes out slightly gooey - you don't want to over bake! Allow the brownies to totally cool before making the marshmallow.

Make the Marshmallow

1. In the bowl of a stand mixer fitted with the whisk attachment, add the gelatin and 3 Tbsp of the water. Give it a little stir and then allow it to thicken while you heat up your sugar.
2. In a small saucepan, add the sugar, agave, salt, and the remaining 3 Tbsp of water. Gently swirl the pan to ensure sugar is totally saturated. Set heat to medium-high (or medium for a gas range) and bring the mixture to a boil. Use a candy thermometer to monitor the sugar's temperature. If your mixture begins to boil too high up the pan, you can use your thermometer to gently swirl the mixture back down or hold the pot up and over the heat. When the mixture reaches 240°F immediately remove from the heat.
3. With your stand mixer running at low speed, slowly pour the hot sugar mixture into the gelatin. Turn the speed to high and whisk until mixture becomes white, thick, and fluffy. I like to wait until I see soft peaks. Immediately whisk in the peppermint and vanilla extracts.
4. Pull the cooled brownies out the pan. Immediately spread the marshmallow over the brownies, using an offset icing spatula to spread and swirl it over the surface. Top with sprinkles, chocolate chips, or crushed peppermint candies.
5. Allow marshmallow to set for at least 4 hours before slicing. For an easy, clean slice, I recommend running a sharp knife under HOT water, wiping clean with a towel, and then carefully slicing - you'll need to heat and carefully* wipe the knife between every slice (I used a thermos to hold the hot water, which allowed me to dip my knife each time). Slice into 9 or 16 brownies.
6. Store leftovers in an airtight container at room temperature. I highly recommend popping a brownie into the microwave for a few seconds before enjoying!

*Be careful when wiping your knife - it's easy to accidentally slice your hand/fingers if you're holding the towel. I recommend setting the towel down and wiping.