In a bowl combine flour, salt and baking soda and whisk to remove any lumps, then set aside.
Grab your stand mixer and on med-high speed cream together butter and both sugars for 5 mins. until light a and fluffy in texture. Remember to scrape down the sides of bowl to get any butter stuck to sides and bottom.
Add eggs one at a time and mix.
Next add the vanilla and peanut butter and mix for another minute.
Now on low speed gradually add in the flour mixture until just but not completely combined.
Finally on low speed or with a spatula add in your chocolate chips and Reese's cups.
Now using a large scoop, scoop the dough onto parchment lined baking sheets and place them in the fridge for 10-15 mins to chill. Place 5 or 6 cookies per pan.
Set your oven to 350°F while your waiting for dough to chill
Remove from fridge and bake for 10-15 mins. For a gooey cookie take them out earlier for a crispy/chewy cookie leave them in longer. Remember they continue to bake while cooling as well.