1In a large bowl, cream together butter and brown sugar. Add egg yolks, one at a time. Stir in vanilla extract. Mix in flour and salt, stirring until completely combined. Cover bowl with plastic wrap and set in the freezer for 10 minutes. (This is will help prevent cracks when you make the center cavity.)
2. While the cookie dough is in the freezer, preheat the oven to 350 degrees and line a cookie sheet with parchment paper (or Silpat!).
3. Using a small cookie scoop, roll cookies into tablespoon-sized balls. Arrange cookies 1-1/2 inches apart on the cookie sheet. Using your thumb, press a deep hole in the middle of the cookie. Make it deep and wide enough so the gummy bears don’t spill out, but not so deep that you crack the sides of the cookie too much. (You’ll get the hang of it after a few tries.)
4. Bake cookies for 8-10 minutes, or until the cookies look almost done. Open the oven and pull the cookie sheet out enough to be able to reach the back row of cookies. Place a single gummy bear in each cookie cavity. Return cookie sheet back to oven and bake until the bottoms are golden brown. The gummy bears will melt completely in about two minutes, so know your oven!
5. Let cookies cool on the cookie sheet for a few minutes, then transfer to a wire rack to cool completely. Enjoy!