1 1/4 cup sugar

6 tablespoons cornstarch

1 teaspoon salt

5 cups whole milk

4 tablespoons unsalted butter, cut into 4 pieces

5 teaspoons vanilla

2 tablespoons water

1 1/4 teaspoons unflavored gelatin

2 cups heavy cream, chilled

14 ounces graham crackers

For the chocolate frosting

¼ cup (½ stick) unsalted butter

¼ cup unsweetened cocoa powder

¼ cup milk

2 cups confectioners’ sugar

1 tsp. vanilla extract

Combine sugar, cornstarch, and salt in a large saucepan.

Whisk milk into sugar mixture until smooth and bring to a boil, scraping bottom with rubber spatula, over medium high heat.

Immediately reduce heat to medium low and cook, continuing to scrape bottom, until thickened and large bubbles appear on surface, 4 to 6 minutes. Off heat, whisk in butter and vanilla.

Transfer pudding to large bowl and place plastic wrap directly on surface of pudding. Refrigerate until cool, about 2 hours.

Stir water and gelatin together in bowl and let sit until gelatin softens, about 5 minutes.

Microwave until mixture is bubbling around the edges and gelatin dissolves, 15 to 30 seconds.

Using stand mixer fitted with whisk, whip 2 cups cream on medium low speed until foamy, about 1 minute. Increase speed to high and whip until soft peaks form, about 2 minutes. Add gelatin mixture and whip until soft peaks, about 1 minute.

Whisk one third whipped cream whipped cream into chilled pudding, then gently fold in remaining whipped cream, 1 scoop at a time, until combined.

Cover bottom of 13x9-inch baking dish with layer of graham crackers, breaking crackers as necessary to line the bottom of the pan. Top with half of pudding whipped cream mixture and another layer of graham crackers.

Repeat with remaining pudding-whipped cream mixture and remaining graham crackers.

To make the frosting, melt the butter with the cocoa powder in a small saucepan. Bring to a light simmer over medium-low heat and let it bubble for about 1 minute.

Whisk in the milk and cook for 3 more minutes, letting the mixture bubble up around the edges.

Remove from the heat and beat in the confectioners’ sugar with a whisk or hand beater.

When the mixture is smooth, add in the vanilla.

While the frosting is still hot, pour it over the top layer of graham crackers and smooth with a knife or spatula dipped in hot water.