Preheat your oven to 350°F (175°C). Grease a 9-inch springform pan and line the bottom with parchment paper for easy removal. In a food processor, combine the chopped dark chocolate and mashed avocado. Pulse until smooth. Add honey, eggs, vanilla extract, and a pinch of salt. Blend until well combined.
Pour the brownie batter into the prepared springform pan, spreading it evenly. Bake for 15-20 minutes or until the edges are set but the center still has a slight jiggle. Remove from the oven and let it cool slightly while you prepare the cheesecake filling.
In a mixing bowl, combine the reduced-fat cream cheese and mashed avocado. Beat with an electric mixer until smooth. Gradually add in the raw organic cane sugar, continuing to mix until well blended. Add the nonfat vanilla Greek yogurt, eggs, and peppermint extract. Mix until everything is creamy and well combined.
Pour the cheesecake filling over the cooled brownie layer in the springform pan. Sprinkle the chopped dark chocolate on top of the cheesecake. Bake in the preheated oven for about 45-55 minutes, or until the center is set but still slightly jiggly.
Once baked, remove the cheesecake from the oven and allow it to cool at room temperature for about an hour. After it has cooled, refrigerate for at least 4 hours, preferably overnight, to allow the flavors to meld and the texture to set.
Before serving, drizzle with dark chocolate sauce if desired. Carefully remove the cheesecake from the springform pan, slice, and enjoy your Mint Gluten-Free Cheesecake With Avocado Brownie Bottom!