Brownie Chalkboard

Brownie Instructions: 

1. Preheat oven to 350°F.
2. Line a 9x13-inch baking pan with non-stick tin foil or with parchment paper that is sprayed with baking spray.
3. Combine flour, cocoa powder, and baking soda together in a bowl.
4. Mix with a fork or whisk until well combined.
5. Combine butter and chocolate in a microwave-safe bowl.
6. Heat on high power for 1 minute.
7. Remove and stir.
8. Let sit for 3 minutes then stir again.
9. Heat for 30 more seconds.
10. Let sit in microwave for 3 minutes then remove and stir until melted.
11. If needed, heat for 10-second bursts of power, stirring after each, until melted.
12. Whisk together the eggs, egg yolks, and sugar until well combined.
13. Pour the chocolate, oil, salt, and vanilla extract into the egg mixture and stir well.
14. Add the flour mixture and stir just until combined.
15. Pour into prepared pan.
16. Bake for 38-42 minutes until the edges are set and the center of feels slightly firm when pressed with a finger.
17. Remove and allow to cool for 20 minutes in pan.
18. Remove from pan and cool completely.
19. Level the top of the brownie using a serrated bread knife to trim off the domed edges.
20. Set a cutting board over the top of the brownie and flip it upside down onto a serving platter, cake board, or cutting board.

Frosting Instructions:

1. Beat butter and shortening using an electric mixer until light and fluffy.
2. Add powdered sugar, 2 tablespoons milk, and vanilla.
3. Beat until smooth and creamy.
4. Scoop out 3 tablespoons of the white frosting and spoon into a pastry bag fitted with a #4 round pastry tip.
5. Set aside.
6. Add peanut butter and 1 teaspoon cocoa powder to the remaining frosting.
7. Beat until well combined, adding additional milk, one teaspoon at a time, if needed to thin out the frosting.
8. Spoon the tan colored frosting into a pastry bag fitted with a #125 petal pastry tip.
9. Pipe a frame of tan frosting around the border of the brownie.
10. Pipe a second layer on top of the first to make the frame thicker.
11. Freeze for 10 minutes. 

Ganache Instructions: 

1. Combine heavy whipping cream and chocolate in a microwave-safe bowl.
2. Heat on high power for 1 minute.
3. Let the bowl sit in microwave for 5 minutes.
4. Remove and stir until melted and smooth.
5. If needed, heat for 10-second bursts of high power, stirring after each, until melted.
6. Pour the chocolate ganache into a thin layer over the brownie in between the peanut butter frosting frame.
7. Let the ganache firm up for at least 2 hours. 

Chalk Board Decoration: 

1. Before serving, dust the powdered sugar over the chocolate ganache.
2. Using a soft bristle pastry brush, sweep the powdered sugar across the chalkboard a few times.
3. Use the white frosting to add letters, numbers, and stick drawings to the chalkboard