Dinosaur Cake

Directions

1. Make the cake: preheat the oven to 350° F. Grease a 13x18-inch baking sheet (half sheet pan) with nonstick spray and line with parchment paper. Spray the parchment paper lightly with nonstick spray, too.
2. In the bowl of an electric mixer fitted with the paddle attachment, cream the butter, sugar, and lemon zest until light and fluffy, 4 to 5 minutes.
3. Add the eggs one at a time, scraping well after each addition. Add the vanilla and mix to combine.
4. In a medium bowl, whisk the flour, baking soda, baking powder, and salt to combine. In a liquid measuring cup, whisk the milk and sour cream to combine.
5. Add 1/3 of the flour mixture to the batter and mix to incorporate. Add ½ of the milk mixture and mix to combine. Repeat, adding alternate additions of flour and milk until both are fully incorporated.
6. Pour the batter evenly into the prepared pan and bake until a toothpick inserted into the center comes out clean, 25 to 30 minutes. While the cake is warm, run a small offset spatula or paring knife around the outside edge to loosen it anywhere it’s stuck. Cool completely in the pan.
7. While the cake is cooling, make the frosting. Place the egg whites and cream of tartar in the bowl of an electric mixer fitted with the whisk attachment.
8. Combine the sugar and water in a medium pot and stir over medium heat until it comes to a boil. When it begins to boil, stop stirring and attach a candy thermometer to the pot (if any sugar crystals have washed up on the sides, brush them away using a pastry brush dipped in cool water). Continue to cook the syrup until it reaches 240°F (final desired temperature).
9. As soon as the sugar hits 230°F, begin whipping the egg whites on medium-high speed. The goal is to have the egg whites at soft peaks when the sugar reaches the 240°F.
10. With the mixer, add the sugar syrup in a slow, steady stream. Continue to whip on high speed until the mixture reaches stiff peaks and the bowl is longer noticeably warm to the touch. The meringue should be smooth and glossy, not clumpy or dry.
11. With the mixer still running, gradually add room temperature butter in 1 tablespoon (14 grams) chunks. Continue adding and mixing until all of the butter is incorporated and the buttercream is light and smooth.
12. Beat in the vanilla and salt and mix to combine. The buttercream can be used immediately or refrigerated in an airtight container for several days.
13. Repeat this process 2 more times until you have 3 batches of the frosting. Put in the refrigerator until ready to use.
14. To assemble the cake, remove the cake from the baking sheet. Use a sharp serrated knife to cut the cake cleanly in half to create two rectangular layers (13 x 9 inch each).
15. Place one cake layer on a platter or baking sheet. Spread an even layer of frosting on top of the cake and spread out evenly with an offset spatula.
16. Place one cake layer on a platter or baking sheet. Spread an even layer of frosting on top of the cake and spread out evenly with an offset spatula.
17. Place another cake layer on top and press down gently. Chill the cake for an hour, minimum, until the cake has gotten very cold.
18. To carve the cake: Place the stencil on top of the chilled cake and secure it in place with toothpicks. Carefully cut around it with a sharp knife until the dinosaur shape emerges. Remove the excess pieces and snack on them. Chill the cut cake shape for 10 to 15 minutes before frosting.
19. Apply a crumb coat to the top and sides of the cake using an offset spatula. Chill for 30 minutes to an hour.
20. Decorate the cake as desired. I think one of the easiest ways to frost is to do as full coverage as you can with a spatula, then do detail work with piping (aka we can use a star tip to cover the spikes, etc. for contrast and detail).
21. Divide the frosting into up to 6 bowls, and tint each a different color (I used one main color for the body, one for contrasting elements, and then multiple colors for the spikes). You can get creative here and do as many colors as you like! I put the frostings into piping bags. You can fit each bag with a tip (such as a round or star tip)—or you can do what I did, and just cut a ¼ inch opening from the tip with scissors. I piped the frosting into little rounds/dots all over the cake, using the different colors to help create the overall look. Be sure to garnish with sprinkles!
22. Refrigerate the cake not serving right away, but bring to room temp again before serving.