In a microwave safe bowl, melt the peanut butter chips on high for one minute. Remove and whisk, being cautious as the bowl could be hot. Continue melting on high in 30 second increments until smooth and lump free. Repeat this for the ½ cup semi sweet chocolate chips in a separate bowl.
Place about two teaspoons of melted peanut butter chips in one of the mold caverns, using the back of a spoon to spread it up to the rim. Repeat with each mold cavern, making 12 peanut butter and 12 chocolate ones for a total of 24 halves. Refrigerate or freeze molds until choclate is solid, about 5-10 minutes.
While cocoa molds are hardening, make the trees. Melt the candy melts according to the package instructions, and then place melted candy melts in a piping bag. Snip the end of the piping bag off, just a little bit at a time because the size of the piping tip hole will be the size of the tree branches. Pipe trees onto a parchment lined cookie sheet, and add sprinkles if desired. Place in the refrigerator to harden up for five minutes.
Remove the cocoa bomb halves from their molds. Fill with 2 teaspoons cocoa plus ¼ teaspoon pure vanilla extract, plus any sprinkles, candy pieces, or mini marshmallows you desire to add to your own! Add 1 teaspoon of espresso powder to the ones your wish to make mocha bombs.
Run a small flat plate under hot water to warm the surface. Dry quickly, and take one of the choclate or peanut butter mold halves and swirl the rim on the warm place to melt slightly. Gently place on top of a filled half and press down carefully to “seal.” Repeat with the rest of the bomb halves, ensuring you use one peanut butter and one chocolate half for each bomb.
Melt the remaining ¼ cup semi sweet chocolate chips in the same manner as the ½ cup. Place melted chocolate in a piping bag and snip a small bit of the tip off. Pipe some drizzle onto each bomb, and top with a hardened Christmas tree candy melt.
To make the peanut butter whipped cream, place the heavy cream, powdered sugar, vanilla extract, and peanut butter in a small to medium sized bowl. Beat with a standing or hand mixer until soft peaks form, about 1 minute.
To use: warm 14-16oz Dutch choclate milk until hot, being cautious of any splatter. Place two bombs in the chocolate milk and stir to melt and combine. Add peanut butter whipped cream, choclate drizzle, and any leftover Christmas trees to the top and enjoy!