In a large mixing bowl, whisk your crushed Oreo crumbs with your melted butter. Make sure all the crumbs are moist and there aren't any dry patches.
Pour the crumbs into a 9" spring form pan. Use a rubber spatula or the bottom of a measuring cup to press the crumbs down into an even layer, you should have the crumbs going up slightly at the sides of the pan. Place in the freezer for 20 minutes.
Cheesecake filling
In a stand mixer with the whisk attachment or using a hand held electric mixer, whisk the cold heavy cream for about 5 minutes until you have stiff peaks. Set aside.
In a stand mixer with the paddle attachment, beat the cream on medium speed until completely smooth - you don't want any lumps at all.
Add in your sifted confectioners' sugar, vanilla extract, cocoa powder, sour cream and red food dye. Beat on medium-high until incorporated and smooth.
Use a rubber spatula to gently fold in your whipped cream, being careful to not deflate the cream.
Pour the filling into your chilled crust. Use a small offset spatula to smooth out the top. Cover in plastic wrap and keep in the fridge overnight. 12 hours is best. Take out of the fridge and remove the sides of the springform pan.
Topping
Just before serving, place your heavy cream and sugar in a medium mixing bowl. Use a hand held mixer or a stand mixer with the whisk attachment and whisk until you have stiff peaks.
Sprinkle over your Oreo cookie crumbs on top of the cheesecake.
Carefully put the whipped cream in a piping bag fitted with a tip (I used the Wilton 1M) and pipe all along the sides of the cheesecake.
Notes
Heavy Cream: If you're based in the UK, use double cream.Food Dye: I used Americolor food dye in the shade Tulip Red. Room Temperature: make sure the cream cheese and sour cream are room temperature before starting this recipe.Cream Cheese: If you're based in the UK, Europe, or your cream cheese comes in tubs, then the cream cheese you are using has a higher moisture content than North American cream cheese. Just before starting the recipe, place your cream cheese in a bowl and place a piece of kitchen roll on top of it, gently squeeze the cream cheese with the paper towel to remove excess moisture. Storage: Keep your cheesecake in the fridge for up to 5 days. It does not freeze well.