Ice Cream Sandwich Cakes - unsalted butter

Method

• Preheat the oven to 325 degrees F. Line the bottom of two 8-inch-square metal baking pans with parchment paper and lightly butter the paper.
• Sift the flour, baking powder, baking soda and salt into a bowl, then whisk to combine.
• Melt the butter in a saucepan over medium heat.
• Add the cocoa powder and whisk until dissolved, about 1 minute.
• Transfer to a bowl and whisk in both sugars until combined.
• Add the coffee, buttermilk, egg and vanilla and whisk until smooth.
• Whisk in the flour mixture until just combined.
• Divide the batter evenly between the prepared pans.
• Bake until a toothpick inserted into the center comes out with a few moist crumbs, 15 to 20 minutes.
• Cool slightly in the pans, then invert onto a rack to cool completely.
• Transfer the cakes to a baking sheet lined with parchment paper, cover with plastic wrap and freeze until firm, about 1 hour.
• Remove the ice cream from the freezer to soften, 10 to 20 minutes.
• Clean and dry the baking pans, then line each with plastic wrap, leaving a 4-inch overhang on all sides.
• Scoop all of the ice cream into one of the pans, packing it to make an even 1-inch-thick layer; smooth with a small offset spatula or the back of a spoon.
• Fold the plastic wrap over the ice cream to cover it, then freeze until solid, at least 1 hour.
• Put 1 frozen cake in the remaining plastic-lined pan.
• Unwrap the ice cream layer and invert it on top of the cake; remove the plastic wrap.
• Cover with the remaining cake, pressing gently.
• Fold the plastic wrap over the cake to cover it and freeze until firm, about 1 hour.
• When ready to serve, unwrap the cake and cut into 9 squares.
• Cut each square in half to make 2 rectangles or triangles.
• Photograph by Levi Brown