Candied Kumquat and Custard Tarts

Name: Candied Kumquat and Custard Tarts
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Cuisine: American, French
Ingredients: 1 1/2 cups Petit Beurre crumbs (substitute graham cracker crumbs); 1/2 cup almond flour; 2 tablespoons granulated sugar; 1/2 cup unsalted butter (melted); 2 cups whole milk; 1/3 cup all purpose flour; 1/2 cup granulated sugar; 1/4 teaspoon kosher salt; 4 egg yolks; 1/4 cup unsalted butter (room temperature); 1 tablespoon vanilla bean paste (substitute vanilla extract); 2 tablespoons kumquat simple syrup (optional); 15-20 kumquats (sliced); 1 cup water; 1 cup granulated sugar