Preheat your oven to 350º.
Whisk together flour and salt in a medium size bowl. Using a mixer, cream the butter and sugar. Add the peanut butter until combined. Add egg yolks and vanilla.
When combined, separate the dough into 2-3 parts, flatten each section slightly and cover with plastic wrap. Working with smaller sections of cookie dough will make it easier to handle when using your rolling pin. You can also keep the sections in the refrigerator that you aren't working with to keep the dough chilled.
I like working with sugar cookie dough much better than pie dough. It's really forgiving and you can re-roll the scraps until it's all gone. Plus, you can roll the dough out in between two sheets of parchment paper really easily and you don't even have to flour your work surface. That's the best part. No mess.
Roll out the dough evenly. Then cut out shapes with your heart-shaped cutter, leaving a little space in between each cookie for baking.
For every pair of 4-inch heart cookies, use the alphabet cookie cutters on one heart. (You can spell out words with 4 to 5 letters easily.) When you press the individual letters into the dough, you may need the help of a toothpick to lift up the letters so they can be removed. So have a few handy. Make sure to save all the letter scraps, too. They can be reused.
Transfer the heart-shaped dough cut outs to your baking sheet. You can leave them right on the parchment paper and that way you wonât disturb the shapes. Genius. I learned this little trick from the book, Cookie Craft and it's made the whole process much more fun.
Bake the cookies for about 10 minutes. Remove and let cool. Then repeat until you have rolled all of the cookie dough and scraps.
When cool, spread a thin layer of raspberry filling on one side of the solid cookie. Sprinkle the other cookie (the one with letter cut outs) with powdered sugar and then gently place on top of the cookie with raspberry filling. Repeat until you have 12 sweet heart cookie sandwiches.