by Dorie Greenspan

This recipe comes to TableFare from Dorie Greenspan as part of her contribution to Spice Inspirations.
When I'm on a tear in the kitchen, creating and testing several new recipes each day, day after day, I switch into taste-and-give mode, meaning I taste everything I make, cut a portion to check out its keeping qualities and then give away the leftovers. (My neighbors love me!) I usually have no regrets - after all, I'll be baking something good the next day - but sometimes a cake comes along that is un-give-away-able, and this is one of those cakes. It's really a simple cake in every way. You mix it in minutes by hand and bake it in an ordinary square pan, spread half of the cinnamon batter into the pan, add chocolate bits and a mixture of cinnamon, sugar and instant espresso, and spread over the rest of the batter. Then it gets a delicious, but equally simple, frosting, a melt of chocolate and butter. It's pretty enough, in a homey way, but there's something about the softness of the cake, the warmth of its cinnamon flavor, the way the swirl of cinnamon, sugar, chocolate and coffee melt into the cake and that really good frosting, that make it a gotta-have-more cake and one that's as good at a brunch as it is as a midnight snack.
Makes 9 squares
For the cake:
1 1/4 cups plus 2 tablespoons sugar
5 1/2 teaspoons cinnamon
1 1/2 teaspoons instant espresso powder
1 3/4 cups all-purpose flour
2 teaspoons double-acting baking powder
Pinch of salt
3/4 cup whole milk
2 large eggs
1/2 teaspoon pure vanilla extract
1 stick plus 2 tablespoons (10 tablespoons; 5 ounces) unsalted butter, melted and cooled
3 ounces finely chopped bittersweet chocolate or 1/2 cup storebought mini chocolate chips
For the frosting:
6 ounces bittersweet chocolate, finely chopped
2 1/2 tablespoons unsalted butter, cut into 4 pieces
Getting ready: Center a rack in the oven and preheat the oven to 350 degrees F. Butter an 8-x-8-inch baking pan and line the bottom of the pan with parchment or wax paper. For easy transportability, place the pan on a lined baking sheet (page 000). Stir 2 tablespoons of the sugar, 2 1/2 teaspoons of the cinnamon and the instant espresso together in a small bowl and set aside.
Working in a bowl that is large enough to hold all the ingredients, whisk together the flour, the remaining 1 1/4 cups of the sugar, the baking powder, salt and the remaining 3 teaspoons of the cinnamon. In another bowl, whisk together the milk, eggs and vanilla. Pour the liquid ingredients over the flour mixture and, still using the whisk, gently stir until you have a homogenous batter. Now, using the side of the whisk or a rubber spatula, fold in the butter with a light touch. Fold only until the butter is absorbed and you'll have a ready-to-bake, smooth, satiny batter.
Scrape one-half of the batter into the pan and smooth the top. Sprinkle the chocolate over the batter and dust with the cinnamon-sugar-espresso mixture; cover with the rest of the batter and smooth the top again.
Slide the pan into the oven and bake 35 to 40 minutes, or until the cake is puffed and begins to pull away from the sides of the pan; a knife inserted into the center of the cake will come out clean. Transfer the cake to a cooling rack and let it rest for 15 minutes before unmolding it onto a rack. Peel off the paper, invert, and cool to room temperature right side up on a rack.
To make the frosting: Put the chocolate and butter in a heatproof bowl and fit the bowl over (but not touching) a pan of simmering water. Cook, stirring gently and often, just until the chocolate and butter melt. Be careful not to overheat the mixture - what you're looking for is chocolate that is smooth, very shiny, thick and spreadable. (You don't want to heat the chocolate and butter so much that they thin out. If you do, it's not tragic - you'll just have to leave the frosting at room temperature for a bit until it thickens a little.) Using an offset metal spatula or a table knife, spread the frosting in generous sweeps and swirls over the top of the cake; allow the frosting to set at room temperature.
Serving: Cut the cake into 9 squares, each about 2 1/2 inches on a side and serve, if you'd like, with whipped cream, crème fraîche or cold sour cream.
Storing: Wrapped in plastic, the cake will keep at room temperature for a day or two or it can be frozen for up to 2 months. It's best to put the cake in the freezer unwrapped and then, when the frosting is firm, to wrap the cake airtight; defrost, still wrapped, overnight in the refrigerator.
Playing Around: Cappuccino Squares. If you like the cappuccino-type flavor of coffee and cinnamon, you can easily switch the balance in this recipe by adding a jolt of coffee flavor to the batter. Just mix 1 tablespoon instant espresso into the milk in the recipe and warm the milk in a microwave oven until it is hot enough to dissolve the coffee. Cool the milk and carry on.
Reprinted with permission from the book Baking, From My Home to Yours by Dorie Greenspan. Copyright © 2006 by Dorie Greenspan. Published by Houghton Mifflin.