You've heard of Brooklyn Blackout Cake, but I bet you've never had one made with carob. I adapted this from Half Baked Harvest and removed all the chocolate for people like me who are allergic or those avoiding caffeine. Don't let carob scare you away. It creates the deepest, darkest, most chocolaty cake you can ever imagine. —Laura Dembowski
Preheat the oven to 350 degrees F. Butter 2 8 or 9 inch cake pans. Line the bottom with parchment and butter the parchment.
Cream the butter, oil, and sugar until light and fluffy. I did this by hand, but a hand or stand mixer will work as well. Add the eggs one at a time, making sure each is mixed in before adding another.
Beat in the vanilla, carob, baking powder, baking soda, and salt. Mix together the flour and cornstarch. Add the flour and cornstarch mix and milk alternately, beginning and ending with the flour.
Divided batter between the two pans and bake for about 25 minutes, until set and a toothpick inserted in the center comes out with only a few moist crumbs. Cool in pans about 15 minutes, before carefully inverting onto plates to cool completely.
Pudding and Frosting
Make the pudding. In a large saucepan, bring 2 ½ cups water, sugar, honey, and 1 cup carob to a boil, whisking occasionally. Meanwhile, in a small bowl whisk together cornstarch and remaining ½ cup of water. Once the sugar mixture comes to a boil, whisk in the cornstarch mixture.
Bring to a boil and cook, whisking constantly, until the mixture thickens substantially, 2-3 minutes. Remove from the heat and stir in the cold butter one piece at a time, followed by the vanilla. Pour into a bowl, cover with plastic wrap and allow to chill until completely cool.
Make the frosting when ready to assemble the cake. Beat butter and sugar using a hand or stand mixer until light and fluffy. Add 1/4 cup carob and vanilla and beat until fluffy and combined. My frosting was creamy and spreadable at this point, but if yours is not, add milk 1 tablespoon, at a time until it is.
Assemble the cake. Slice once of the cakes in half horizontally. Place on a cake stand. Cover with a generous amount of pudding. Place the other half of the cake on top. Cover that with a generous amount of pudding. Slice the other cake in half horizontally. Place the nicer of the two halves on top. Cover the cake with the frosting. I poured some additional pudding on top too.
Take the final, unused layer of cake and crumble it up with your hands. Push the crumbs into the frosting on the top and sides of the cake. Refrigerate for at least two hours before serving. Cake may be stored in an airtight container in the refrigerator for up to 3 days.