Cream the softened butter and dark brown sugar together until light and fluffy.

Add the egg and vanilla and mix until fully incorporated.

In a separate bowl, whisk together the flour, baking soda, baking powder, and salt.

Add the dry ingredients to the butter mixture and mix just until combined.

Add the dark chocolate chips and milk chocolate chips and mix until evenly distributed.

Place the cookie dough between two sheets of parchment paper. Roll and shape into approximately a 10-inch round, about ¾ inch thick.

Transfer the dough to the freezer and freeze until completely firm.

Preheat oven to 325°F. Place a fresh sheet of parchment paper onto a round pizza pan and transfer the frozen cookie dough round onto the pan.

Bake from frozen for 35 minutes.

Allow the cookie cake to cool completely before decorating.

Beat the softened butter, powdered sugar and vanilla until light, smooth, and fluffy (for Vanilla Frosting).

Beat the softened butter, powdered sugar and cocoa powder and mix until light and fluffy (for Chocolate Frosting).

Add the corn syrup and vanilla and mix until smooth (for Chocolate Frosting).

While the mixer is running, gradually add the melted dark chocolate and beat until the frosting is completely combined and smooth (for Chocolate Frosting).

Transfer the vanilla and chocolate frostings to separate piping bags fitted with an Ateco #848 tip.

Pipe alternating dollops of vanilla and chocolate frosting around the outside edge of the completely cooled cookie cake, placing the tip against the cookie, applying pressure, then pulling straight up to create the pointed star shape.

Slice and serve.