Warm a large sharp knife under hot water, dry it, then carefully and gently cut around the seam of the Easter egg until it separates into two halves.
Crush the digestive biscuits into fine crumbs using a food processor or by bashing in a bag with a rolling pin.
Melt the butter in the microwave or on the stove and combine it with the biscuit crumbs until the mixture resembles wet sand.
Press the biscuit mixture evenly into the base of each Easter egg half using the back of a spoon; chill in the fridge while preparing the filling.
Beat the cream cheese, icing sugar, and vanilla extract together in a bowl with an electric mixer until smooth.
Add the double cream and mix until thickened and the filling holds its shape.
Divide the cheesecake filling between the Easter egg halves, smoothing the top with a small palette knife or spoon.
Refrigerate the filled Easter eggs to set for 2 hours.
Melt the dark chocolate in the microwave in short bursts, stirring until smooth.
Drizzle melted chocolate over the cheesecake and decorate with mini eggs and Kit Kat bunnies or other preferred Easter treats.
Serve immediately or store in the fridge for up to 3-4 days.