Preheat the oven to 350°F (175°C).
For the chocolate filling, melt the semi-sweet baking chocolate in a microwave. Add the butter and stir until smooth.
In a separate bowl, whisk together the eggs, milk, vanilla extract and sugar. Slowly pour this mixture into the melted chocolate and butter mixture, stirring continuously.
Pour the filling into both of the pre-made Oreo cookie crusts. Bake for 20 minutes or until a knife inserted comes out clean. Let cool completely before adding toppings.
For the white chocolate layer, melt the white baking chocolate in a microwave. When melted, stir in the mint extract and set aside.
To make the whipped topping, beat together the powdered sugar, vanilla extract and heavy cream until soft peaks form. Gently fold in the crushed peppermint candies.
Spread the white chocolate layer over both of the cooled pies. Top with the whipped topping, then sprinkle with the remaining peppermint candies to garnish.