To Make The Brownies:

1. Preheat the oven to 350°F.
2. In a large bowl, whisk together the gluten-free flour, cocoa powder, cornstarch, baking powder, and salt until everything is one uniform color.
3. In a microwave-safe bowl, melt the vegan butter until hot and fully liquid. Then stir in the granulated sugar, brown sugar, prepared flax eggs, peppermint extract, and vanilla extract until fully dissolved and thick.
4. Add the hot butter mixture to the bowl of dry ingredients and mix until mostly smooth. It should be pretty thick.
5. Fold in the dark chocolate chips, careful not to overmix the brownie batter.
6. Line an 8x8 baking pan with parchment paper and pour the brownie batter evenly into the pan, smoothing out the top.
7. Bake the brownies in the preheated oven for about 20-23 minutes. Just until the edges slightly pull away from the pan, but the center is still moist.
8. Allow the brownies to cool in the pan before placing them in the fridge or freezer to chill completely.

To Make The Frosting:

1. Start by melting the vegan white chocolate slowly in the microwave. 30-40 second intervals at half power is best, so you don't end up with burnt and dry chocolate. Allow the smooth melted chocolate to cool to room temperature.
2. Allow the vegan butter to soften slightly before cutting it into 4 chunks and adding it to a stand mixer or large bowl with a hand mixer.
3. Beat the butter until smooth before adding in the cooled white chocolate. Beat the mixture together before adding the peppermint extract and powdered sugar. Add one cup of powdered sugar at a time until the frosting is thick and fluffy, scraping down the side of the bowl as needed.
4. Store the frosting in the fridge until ready to frost the brownies.

To Assemble:

1. Once the brownies have chilled completely, you can slice them into 9 squares while they are still in the pan before lifting them out onto a plate.
2. Using an icing spatula or knife, frost the top of the brownies like you would a cake, and then sprinkle the crushed peppermint candy on top. Now you can easily slice through the frosting using the pre-cut seams as a guide.