Preheat the Oven: Begin by preheating your oven to 350°F (175°C) and lining a muffin tin with cupcake liners.
Prepare the Batter: In a large mixing bowl, combine 1 box of vanilla or chocolate cake mix with 3 large eggs, 1/2 cup of vegetable oil, and 1 cup of water. Mix well until all ingredients are fully incorporated and the batter is smooth.
Fill the Muffin Tin: Carefully pour the batter into the lined muffin tin, filling each liner about 2/3 full. This allows enough room for the cupcakes to rise without overflowing.
Bake the Cupcakes: Place the muffin tin in the preheated oven and bake for 18-22 minutes, or until a toothpick inserted into the center comes out clean. Once baked, remove from the oven and let the cupcakes cool completely on a wire rack.
Prepare the Frosting: While the cupcakes cool, make the frosting. In a mixing bowl, beat 1 cup of softened unsalted butter until creamy. Gradually add in 4 cups of powdered sugar while mixing on low speed to avoid a sugar cloud. Next, pour in 1/4 cup of heavy cream, 1 tsp of vanilla extract, and a few drops of green food coloring. Beat until the mixture is fluffy and well-combined.
Pipe the Frosting: After the cupcakes have cooled completely, use a piping bag to pipe the green frosting onto each cupcake to create the shape of a Christmas tree. Start from the bottom in a circular motion and work your way up to create layers for the tree.
Add Decor: Decorate your frosted cupcakes with mini chocolate chips or candy as ornaments and sprinkle red and green sprinkles generously over the frosting. Top each tree with a mini star-shaped candy for a finishing touch.
Create the Trunk: Insert a pretzel stick into the base of each cupcake to represent the trunk of the tree, adding a fun crunch to every bite.