In the bowl of a stand mixer, add softened butter, sugar, egg yolks and vanilla. Beat with the paddle attachment at medium-low speed, scraping the bowl often, until light and creamy. Add one third of the flour; beat at low speed until just combined, repeat with remaining flour. Cover with plastic wrap and refrigerate at least 1 hour.

Preheat oven to 375 degrees.

Roll dough into 1-inch balls. Place 2 inches apart onto parchment paper lined baking sheets. Make indentation in center of each cookie with your thumb or whatever tool you choose. Bake for 7-10 minutes or until edges JUST begin to brown.

Repeat indentation once cookies are done baking, if necessary. Cool completely on wire cooling racks.

Melt the caramel and heavy cream in the microwave, stirring every 30 seconds or so until it is fully melted and smooth. Add pinch of salt and stir. Using a teaspoon measuring spoon, fill each indentation with the caramel.

Pour vegetable oil over chocolate chips and melt the chocolate in the microwave, stirring 30 seconds at a time until melted and smooth, and scoop into a ziploc bag. Barely snip the corner and drizzle over the cookies.