Chocolate cookie dough is rolled in nuts and topped with buttercream and chocolate kisses to create these thick and chewy Chocolate Cream Thumbprint Cookies.
Cream the butter and sugar together. Add the egg yolk, milk, and vanilla. Mix until combined.
In a separate bowl, combine the flour, cocoa, and salt. Add all at once to the chocolate mixture. Mix until combined. CHILL DOUGH in the refrigerator for 1 hour or until sturdy enough to handle. (Sometimes I skip the refrigerator, but it's just easier to handle if you refrigerate it first.)
Meanwhile, unwrap the chocolate kisses and prepare the buttercream by whisking the ingredients together in a small bowl. Scoop the buttercream into a zip-top bag and cut off the corner.
Make 24 round balls with the chocolate cookie dough. Whisk the egg white until foamy. Dip the cookie dough balls into the egg white and then into the nuts. Cover each cookie dough ball completely. Place nut covered dough balls onto a prepared baking sheet (lined with parchment paper, a silicone baking mat, or greased with pan spray).
Make an indent in the top center of each cookie with a ½ teaspoon measuring spoon.
Bake at 350 degrees Fahrenheit for 10 to 12 minutes. Allow to cool slightly (5 minutes) before transferring to a cooling rack. Place milk chocolate kisses in the center and allow to melt slightly (1 or 2 minutes; long enough for the bottom to melt, but the top is still solid).
Lift the chocolate kisses back up and pipe/squeeze some of the prepared buttercream into the center of the cookie. Place the chocolate back on top. Allow cookies to cool completely. Store in an airtight container up to 5 days.