• Preheat oven to 350°F/177°C. Line a 9 x 13-inch baking dish with parchment paper.
• In a large microwave-safe mixing bowl, combine ½ cup unsalted butter and 8 ounces semi-sweet chocolate chips morsels. Melt in the microwave in 30-second intervals, until melted and smooth.
• To the chocolate mixture, add 1 cup granulated white sugar, 1 cup light brown sugar (packed), 2 teaspoons pure vanilla extract, 2 large eggs, 2 egg yolks , ¼ cup unsweetened cocoa powder, and ½ cup vegetable oil. Stir to combine ingredients.
• Stir 1¼ cup all-purpose flour into the chocolate mixture. Note 1
• Spread the brownie batter into the prepared pan.
• Bake in the preheated oven until a toothpick inserted in the center comes out clean, 30 to 35 minutes. Set aside.

How to make the Ganache

• In a small saucepan over low heat, add 4 Tablespoons unsalted butter, ½ cup sweetened condensed milk, and 10 ounces green candy melts, stirring until smooth. Remove from the heat.
• Top the cooled brownies with the ganache and spread it over the brownies. Quickly sprinkle the brownies with the ¼ cup rainbow chip sprinkles
• Set aside to cool completely.
• Once cool, use the Christmas tree cookie cutter and cut out trees.
• The Christmas tree brownies are ready to serve.