Sift together the flour and cocoa powder. Set aside.

Cream together the butter and sugar until light and fluffy, about 3 minutes. Add the egg yolk, sea salt, and vanilla.

Add the flour mixture in 3 additions.

Separate the dough into two and roll into a log shape. Wrap the dough in parchment or plastic wrap. Refrigerate for at least 4 hours, preferably overnight.

Slice the cookies and bake on a parchment lined baking sheet. Place the cookies in a preheated 350 degree oven for about 12 minutes. Cool on a rack.

I put the peanut butter pie filling in a piping bag fitted with a large round tip. I put a teeny bit of filling on the plate so that it acts as glue and the cookies will not move around on the plate. Place a cookie on top and pipe some filling. Do this again. You should have 2 layers of filling and 3 cookies.

Drizzle caramel sauce over the top and sprinkle with peanuts.