This Vintage Dessert Casserole Is So Good, I Had to Track Down My Mom’s Handwritten Recipe

When I was a kid, most of Mom’s culinary greatest hits had fairly self-explanatory names. Chicken noodle soup. Hot ham and cheese sandwiches. Beef mushroom. When it came time for dessert, though, my two older sisters and I knew it was a really good day when Frozen Yum Yum was on the menu.

Since leaving home to attend college 20 years ago, I haven’t savored a slice—and honestly forgot about it. But after perusing this tempting round-up of ice cream treats, the decadent slices Mom deemed “Frozen Yum Yum” rushed back to mind. I couldn’t resist calling her to get the backstory—and the recipe—so I could recreate the delightfully named dessert casserole and pass along the tradition.

First, What Is Frozen Yum Yum?

Frozen Yum Yum has been in my mom’s recipe card collection longer than I’ve been alive, so I asked her for the dish and how it came into her life.

A college friend had talked about loving a family dessert, she says, “so I asked for the recipe.” But Mom waited for her girls to be “old enough to enjoy it” before giving Frozen Yum Yum a try in her kitchen.

Not to be confused with Texas Yum Yum pudding pie, Cherry Yum Yum cheesecake bars, or Granny’s Lemon Yum Yum with cream cheese-whipped cream, Frozen Yum Yum is a dessert casserole that most resembles an ice cream cake with a graham cracker crust, an ultra-easy chocolate mousse-like layer, and a softened vanilla ice cream topping with a few more graham cracker crumbs for good measure.

Confirming that it “was a very special occasion treat,” Mom recalls that “we’d have it more in the summer, and sometimes those who had summer birthdays [like my oldest sister, Amy, and me] might request it for their birthday cakes. The ice cream and graham crackers are a great combination.”

I remember standing at Mom’s hip as she’d whip softened butter with powdered sugar, and I’m pretty sure this is where I first learned that you could separate eggs. (After incorporating the egg yolks into the chocolate mousse mixture, you fold in whipped egg whites to lighten up the consistency.)

As a kid, what I adored most about Frozen Yum Yum—and why I occasionally asked for it in lieu of Funfetti Cake—is the contrast. Crunchy meets creamy. Chocolate meets vanilla. Somehow, the whole is so much greater than its parts, and only seven ingredients are required.

A Word on Frozen Yum Yum’s Ingredients

Think of Frozen Yum Yum as a streamlined older sister of a Dairy Queen ice cream cake. Here’s all you’ll need to try it at home:

• Softened butter: Salted or unsalted; either works. Mom would always set out the 1 1/3 sticks of butter about an hour before we’d start assembly, but if you’re crunched for time, use this foolproof trick to soften butter fast.
• Powdered sugar: The chocolate layer of Frozen Yum Yum is like a mash-up of chocolate frosting and chocolate mousse. Powdered sugar, also known as confectioners’ sugar, lends sweetness. Once you cream it with the butter, it lightens up the texture beautifully.
• Eggs: You’ll need 3 eggs, with the yolks and whites separated. In a small bowl, use a fork or whisk to mix the yolks until they’re even in consistency. Whip the egg whites to soft peaks to fold in as you finish the chocolate mixture. If you can find them, pasteurized eggs are a wise move since this is a no-bake dessert.
• Unsweetened chocolate: Mom always used a bar of baking chocolate. The unsweetened nature is ideal since the powdered sugar certainly makes the whipped layer sweet enough. That said, if you can’t find or don’t love unsweetened, a few squares from a bar of semisweet (50% to 60% cacao) or dark chocolate (60% to 99%) are solid substitutes. Melt the chocolate in a double boiler on the stove. Or follow Mom’s lead and place the chocolate in a heat-safe bowl and microwave at 50% power in 30-second intervals, stirring between each, until it is melted.
• Salt: Just a pinch is perfect to accent the sweet nature of this dessert.
• Vanilla extract: Pure vanilla extract is what adult me would often choose, but here? Imitation vanilla tastes like childhood (and boxed cake mix!). Take your pick.
• Chopped nuts: These are completely optional. In fact, when discussing Frozen Yum Yum with Mom, she forgot they were even listed on her recipe card. If you decide to include them, try chopped pecans, walnuts, or peanuts.
• Graham cracker crumbs: Crusts don’t come much easier than this. Just crush graham cracker crumbs in a food processor—or go old-school and use a zip-top bag and a rolling pin (my favorite way to do it as a kid)—then press them into the bottom of the pan. No extra butter required. I’m already dreaming about whipping up Frozen Yum Yums with bases made with crumbled chocolate graham crackers, crushed waffle cones, and crumbled shortbread cookies. 
• Vanilla ice cream: When I recently asked chefs to share their favorite vanilla ice cream, Tillamook came out on top. Our internal taste test resulted in Häagen-Dazs (Ina Garten’s MVP) coming out on top. Snag a quart of your personal pick for the best vanilla ice cream. Once you’ve tried the classic chocolate-vanilla rendition, consider swapping in another flavor of ice cream that plays nicely with chocolate, such as cherry, strawberry, cookies and cream, or cookie dough.

How to Make Frozen Yum Yum Casserole

As written, this ice cream dessert makes a party-sized portion: A 9 x 13-inch pan, which Mom would often slice into 15 generous servings. If you prefer a smaller quantity, halve the ingredients and build your Yum Yum in a 9-inch round. For individual portions, assemble Frozen Yum Yum “cupcakes” in a muffin pan. (The full recipe below should treat you to about 24 yummy cupcakes.)

Yield: About 15 to 18 servings

Ingredients

• 2/3 cup softened butter, plus more for greasing the pan
• 2 cups powdered sugar
• 3 egg yolks, slightly beaten (pasteurized if possible)
• 2 ounces unsweetened chocolate, melted
• Pinch of salt
• 1 teaspoon vanilla extract
• 1/2 cup chopped nuts
• 3 egg whites, whipped into soft peaks
• 2 cups graham cracker crumbs, or about 16 full graham cracker sheets (or more if you prefer a thicker crust)
• 1 quart vanilla ice cream

Directions

1. Cream together butter and powdered sugar. Add egg yolks, melted chocolate, salt, vanilla, and nuts. Fold in egg whites. 
2. Butter the bottom of a 9- x 13-inch pan. Pat graham cracker crumbs on the bottom of the pan. Reserve a few crumbs to sprinkle on top of the dessert. 
3. Pour chocolate mixture over crumbs, and freeze for 2 hours. Remove from freezer, and spread with softened vanilla ice cream. Sprinkle remaining crumbs on the top, and return to the freezer. Serve frozen.