Begin by crushing the graham crackers using a food processor until they form fine crumbs. Melt the unsalted butter and combine it with the crumbs, mixing until the texture resembles wet sand. Press this mixture firmly into the bottom of paper baking cups or a mini springform pan, creating an even layer. Set aside while preparing the fillings.

In a microwave-safe bowl, melt the semi-sweet chocolate in 30-second intervals, stirring until smooth. Allow it to cool slightly before adding the heavy cream, mixing thoroughly. Then, add in the cream cheese and powdered sugar, blending until the mixture is completely smooth and creamy. Spread this chocolate filling evenly over the graham cracker crust.

In a separate mixing bowl, combine the room temperature cream cheese, peanut butter, powdered sugar, and vanilla extract. Use an electric mixer to blend until the mixture is velvety and well-combined. Gradually add the heavy cream and mix until the filling is light and fluffy. Gently spread this peanut butter filling over the chocolate layer, smoothing it with a spatula.

Melt additional semi-sweet chocolate in a microwave-safe bowl, then stir in heavy cream and a splash of oil for a glossy finish. Once combined, carefully pour the topping over the peanut butter layer, ensuring an even coating.

Cover the mini cheesecakes with plastic wrap and place them in the refrigerator. Allow them to chill for at least 30 minutes to firm up and meld together.

Once chilled, remove the cheesecakes from the refrigerator. If using, sprinkle chopped peanuts and mini chocolate chips on top for added texture and flavor. Carefully remove the mini cheesecakes from their cups before serving.