Preheat the oven to 350°F (177°C). Lightly grease a 9-inch tart pan with a removable base with nonstick spray.

Make the crust: If you’re starting out with full graham crackers, use a food processor or blender to grind them into fine crumbs. Stir the graham cracker crumbs and granulated sugar together in a medium bowl, and then stir in the melted butter. The mixture will be thick, coarse, and sandy. Try to smash/break up any large chunks. Pour the mixture into the prepared tart pan. With medium pressure using your hand, pat the crumbs down into the bottom and up the sides to make a compact crust. Do not pack down with heavy force because that makes the crust too hard. Simply pat down until the mixture is no longer crumby/crumbly.

Bake the crust for 10 minutes. Set aside on a cooling rack.

Make the cranberry filling: In a medium saucepan over medium heat, combine the cranberries, orange juice, and sugar. Bring to a boil and cook, stirring with a silicone spatula or wooden spoon, until the cranberries have all burst, about 10 minutes. You can mash them against the sides of the saucepan with your spatula to help them along. Remove from heat and allow to cool for at least 20 minutes.

Transfer the cranberry mixture to a high-powered blender or food processor and puree until completely smooth, and no specks of cranberry skins remain. Pour the cranberry puree back into the saucepan.

In a small bowl or liquid measuring cup, combine the egg, egg yolks, cornstarch, and salt. Whisk or stir with a fork until completely combined and smooth. Pour and whisk the egg mixture into the cranberry puree.

Return the saucepan to the stove over medium heat and allow the cranberry curd to come to a boil, stirring constantly. Once boiling, reduce the heat to medium-low and simmer, stirring with a silicone spatula and scraping the bottom and sides of the saucepan to keep the curd from sticking, until thickened, about 5–7 minutes.

Remove from heat and whisk in the butter and vanilla extract until the butter is melted and fully incorporated. Pour the filling into the crust and smooth the top. Let cool at room temperature for 30–45 minutes, and then place in the refrigerator and chill for at least 6 hours, or overnight.

Make the whipped cream: In a large bowl using a handheld or stand mixer fitted with a whisk attachment, whip the heavy cream, sugar, and vanilla extract on medium-high speed until medium peaks form, about 3 minutes.

Spread the whipped cream on top of the tart. Garnish with sugared cranberries, if desired. Remove the rim of the tart pan, slice, serve, and enjoy!

Cover and store leftover tart in the refrigerator for up to 3 days.