Preheat the oven to 375 F. Line two cookie sheets with parchment or silicone liners; set aside.

In a large bowl, cream together the butter and tahini until creamy and well-blended. Add in the white and brown sugars and beat until fluffy. Add in the egg and vanilla, and beat until incorporated. Add in the flour, salt, and baking soda, and mix until dough comes together.

Shape dough into 1-inch balls, place on the prepared cookie sheet, and make an indentation in the center of each with your thumb. Bake cookies 10-12 minutes.

While cookies bake, make your chocolate filling. In a small microwave-safe bowl, combine the chocolate chips and heavy cream. Microwave in 15 second intervals, stirring in between each, until chocolate is smooth and creamy. Transfer the chocolate mixture to a ziploc baggie.

When cookies are baked, remove from oven and press down the indentations in the center of each cookie again. I find that a cork from a wine bottle is the perfect size!

Grab the baggie of chocolate, snip the corner, and fill the center of each cookie with the chocolate cream.

Let cookies cool completely before enjoying!