Ice Cream Fudge Cake

Cooking spray
1/4 cup light corn syrup
1 3/4 cups heavy cream, divided
1/2 stick unsalted butter
2/3 cup granulated sugar
1/2 cup unsweetened cocoa powder, plus more for serving
Salt
3 pints vanilla ice cream
18 graham crackers
1 tablespoon confectioners' sugar
Unsweetened cocoa powder

STEP 1
Lightly coat an 8-inch square cake pan with cooking spray; line pan with plastic wrap, leaving a 6-inch overhang on two sides. Freeze pan at least 10 minutes.

STEP 3
Evenly press softened ice cream into pan. Top with a single layer of graham crackers, breaking to fit. Drizzle with 1/4 cup fudge sauce and freeze 15 minutes. Repeat twice, omitting sauce on final layer. Wrap in plastic and freeze until firm, 8 hours (or up to 3 days). Cover and refrigerate

STEP 4
To serve, invert pan and run under tepid water to loosen cake. Invert onto a platter and remove plastic. Microwave fudge sauce in 30-second increments until pourable. Pour over cake and freeze to solidify, 5 minutes.

STEP 5
In a large bowl, using a mixer, whip 1 1/2 cups cream and confectioners' sugar on high until stiff peaks form, 3 to 5 minutes. Dollop cake with whipped cream and dust with cocoa. Serve immediately.