Begin by finely crushing the 13 Oreos in a food processor until they resemble sand. In a mixing bowl, combine the crushed Oreos with the melted butter. Stir until the crumbs are evenly coated. Press the mixture into the bottom of serving glasses or a large dish to form a crust. Set aside.
In a small bowl, combine the cold water and gelatin powder. Let it sit for about 5 minutes until it blooms and thickens. Once bloomed, gently heat the mixture in a saucepan over low heat, stirring until the gelatin is fully dissolved. Remove from heat and allow to cool slightly.
In a large mixing bowl, whip the heavy cream using an electric mixer until soft peaks form. Be careful not to over-whip; the cream should be fluffy and light. Set aside.
In another mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Gradually add in 1 cup of powdered sugar and mix until well combined.
Mix in the mint extract, peppermint extract, and the slightly cooled gelatin mixture into the cream cheese until fully incorporated. If desired, add a few drops of green and yellow food coloring to achieve your preferred shade of mint green.
Gently fold the whipped cream into the cream cheese mixture using a spatula. Be careful to maintain the light and airy texture. Once combined, fold in the finely chopped chocolate, distributing it evenly throughout the mousse.
Spoon the mint chip cheesecake mousse over the prepared Oreo crusts in your serving glasses. Smooth the tops with a spatula and refrigerate for at least 4 hours or until fully set.
Before serving, top each mousse with a dollop of sweetened whipped cream, a sprinkle of finely chopped chocolate, and a sprig of fresh mint for an extra touch of elegance. Enjoy your Mint Chip Cheesecake Mousse!