Place bowl of stand mixer in the freezer for 10-15 minutes.
Prepare pan with parchment paper if using a loaf pan or baker - extend paper past edge of pan in order to lift the cheesecake out.
Crush Oreo Cookies to a fine crumb (food processor works best); combine with melted butter. Press into bottom of pan.
Take bowl out of freezer, place in stand mixer and whisk the heavy cream. Begin slowly, then increase speed. When cream begins to form, add 3T powdered sugar and 1 tsp vanilla.
In separate bowl, whip together the cream cheese and 2T powdered sugar. If preparing a chocolate cheesecake - add the melted chocolate to the cream cheese and omit the vanilla. Gently fold in 1/2 of the heavy whipped cream.
Smooth cream cheese over Oreo Crust. Pop into freezer for a 10 minutes.
Evenly smooth the second half of the whipped cream on the cheesecake; refrigerate at least 3-4 hours or overnight.
Garnish with chocolate shavings, Oreo cookies, fresh fruit, etc.