Truffle-Filled Cookie Tarts

Directions

1. Preheat oven to 400°. In a large bowl, beat butter and sugars until blended. Beat in egg and vanilla. In another bowl, whisk flour, cocoa and baking soda; gradually beat into creamed mixture.
2. Shape level tablespoons of dough into 2-1/2-in.-wide patties. Press onto bottoms and up the sides of greased mini-muffin cups.
3. Bake until set, 8-10 minutes. Immediately press a deep indentation in center of each with the end of a wooden spoon handle. Cool in pans 5 minutes. Remove to wire racks to cool completely.
4. For filling, in a small heavy saucepan, combine chocolate chips, cream and butter; cook and stir over medium heat until smooth. Remove from heat.
5. In a small bowl, whisk a small amount of hot mixture into egg yolks; return all to pan, whisking constantly. Cook over low heat, stirring constantly, until mixture is thickened and a thermometer reads at least 160°, 15-17 minutes. Do not allow to boil. Immediately transfer filling to a bowl; cool 20 minutes, stirring occasionally.
6. Spoon 1 tablespoon filling into each crust. Top with sprinkles. Refrigerate until cold, about 1 hour.