Prepare the Biscuit Base: Take your 300g of Oreo biscuits and crush them finely. You can do this by placing them in a sealed plastic bag and crushing them with a rolling pin until they resemble dark, fine soil, or use a food processor for a quicker, more uniform crumble. Once crushed, pour in the 100g of melted unsalted butter and mix well until the biscuit crumbs are evenly coated and appear moist and sticky. This forms a cohesive base.

Form the Cup Bases: Line a 12-hole muffin tin with paper cupcake cases. Distribute the buttery Oreo mixture evenly among the 12 cases. Use the back of a spoon or your fingertips to firmly press the mixture down into the bottom of each case, creating a compact, dark base. Once pressed, place the muffin tin in the fridge to chill for at least 15 minutes while you prepare the filling.

Create the Cream Cheese Mixture: In a large mixing bowl, beat the softened 250g full-fat cream cheese with an electric mixer until it's light and fluffy, taking on a pale, creamy hue. Gradually add the 100g of icing sugar, beating until fully incorporated and the mixture is smooth and sweet-smelling. Stir in the 1 teaspoon of vanilla extract. If using, gently fold in the 150g of melted and cooled white chocolate until just combined; the mixture will look thick and glossy.

Whip the Cream: In a separate, clean bowl, pour in the 300ml of double cream. Using an electric mixer, whisk the cream on a medium-high speed until it forms soft peaks. You'll notice the cream becoming much thicker and holding its shape, with a lovely, airy texture. Be careful not to over-whisk, or it might become grainy.

Combine and Fill: Gently fold the whipped double cream into the cream cheese mixture using a spatula. Do this in two additions, taking care not to knock out too much air. The goal is a light, airy, and uniform mixture that smells divinely sweet and vanilla-scented. Spoon or pipe this creamy filling over the chilled Oreo bases in each cupcake case, filling them almost to the top. The filling should look wonderfully smooth and inviting.

Chill and Top: Once all the cups are filled, loosely cover the muffin tin with cling film and return it to the fridge to chill for a minimum of 4 hours, or ideally overnight. This chilling time is crucial for the cheesecake to set properly, firming up to a delightful, scoopable texture. Before serving, sprinkle the top of each cup with the extra 50g of roughly chopped Oreo biscuits for a satisfying crunch and visual appeal.