Preheat the oven to 300 and lightly grease and line an 8x8 square baking tin.
In a stand mixer, beat the butter, cream cheese, salt, sugar, baking powder, and vanilla extract until well combined.
Add the eggs one at a time, beating well after each; the mixture may look slightly curdled/grainy. After adding the final egg, beat at high speed for 3 minutes. After all the eggs are incorporated, fold in the milk.
Sift in the flour and fold in gently, being careful not to overmix. At this stage, the batter will be thick but still pourable. Color the batter your desired shade of green and then spoon into the tin, leveling the top.
Bake at 300 degrees for 40-45 minutes or until a toothpick inserted in the center comes out clean.
Let the cake cool in the pan for about 10 minutes and then turn out onto a wire rack to cool completely.
Once the cake is completely cooled, trim any caramelization off the sides and bottom and level the cake. Cut into 9 equal squares.
Melt 1/3 cup dark chocolate chips in the microwave for 30 seconds, then stir. Melt in 10 second increments, stirring after each one, until smooth. Add the melted chocolate to a disposable piping bag.
Melt white chocolate chips in the microwave in 10 second increments stirring well in between each one until melted. Be careful because white chocolate overheats and seizes VERY easily. Do this part slowly. Color it green to match your cake.
Dip a lollipop stick into the green chocolate then insert into the cake pops and allow them to set until firm. You can speed this process along by sticking them in the freezer for 5 minutes.
Then, take some unmelted white chocolate chips, turn them upside down and press them into the cake squares to make the base of the eyes. Pipe a circle of dark chocolate on top to finish the eyes.
Pipe the mouth and hair with the rest of the melted dark chocolate, allow to set for 15 minutes.
Serve and enjoy!