Preheat your oven to 375°F. Spray an 11-inch tart pan with a removable bottom generously with baking spray and set it aside.

In a medium mixing bowl, sift together the almond flour, sugar, and salt through a fine mesh sieve to remove any clumps in the almond flour. In a separate small mixing bowl, whisk together the melted butter, egg, and vanilla then add it to the flour mixture. Mix the dough with a wooden spoon until all of the flour is moistened and it starts to clump together.

Gently press the crust into the bottom and up the sides of your prepared tart pan, trying to make it as uniform as possible. It takes me about 10 minutes to make the crust neat. Bake the crust for 7 minutes in the preheated oven. Lower the oven temperature to 350°F.

Add the pumpkin puree, eggs, egg yolks, brown sugar, heavy cream, milk, vanilla, pumpkin pie spice, cardamom, and salt a to a large mixing bowl and whisk until smooth. For an extra-smooth filling, strain the custard through a fine mesh sieve or pour it directly into the prepared crust, and smooth it out into an even layer.

Bake the tart for 35 to 40 minutes until the center is set or until a toothpick inserted into the center comes out clean. Allow the tart to cool completely on a wire rack then chill it in the refrigerator for at least 2 hours, up to overnight.

Add the egg whites and salt to the scrupulously clean bowl of a stand mixer fitted with the whisk attachment. Beat the egg whites and salt on low (2-3 on a stand mixer) until frothy then add the cream of tartar. Beat on medium (4-6) until smaller bubbles form then gradually add the sugar, a tablespoon a time, and beat on medium-high until glossy and stiff peaks form. Beat in the vanilla extract.

Top the chilled tart with meringue by either spooning the meringue into a piping bag fitted with a star tip and piping meringue around the edge of the tart or spoon dollops of meringue on top of the tart and use the back of the spoon to create swoops and peaks in the meringue.