Preheat oven to 350 degrees.
In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
In a stand mixer (or in a large bowl with a hand mixer), cream together stick of butter and two kinds of sugar.
Add the peanut butter and vanilla and blend together.
Mix in the flour mixture until just combined (taking care not to over mix).
Place dough on a large sheet of parchment paper. And then place another sheet of parchment paper over the top. Roll the dough out until it’s about ¼-inch thick. And put it in the fridge to chill for at least 30 minutes.
Once it’s chilled, place dough on counter and remove top layer of parchment paper. Cut hearts (or any shape) out of the dough with a cookie cutter. If you re-roll dough, be sure to chill the dough between parchment paper again.
On a parchment paper-lined baking sheet, place hearts about one inch apart (you’ll need multiple baking sheets).
Bake at 350 degrees for about 7-9 minutes, until cookies are lightly golden at edges.
Remove from oven, let cool a bit on baking sheet, and then move to a wire rack to cool completely.
Put baking chips in a double boiler (or a heat-proof bowl over a saucepan filled with water) and bring water in the bottom of boiler to a boil.
Stir the chocolate with a wooden spoon until it's evenly melted and smooth.
Dip half of each cookie into the chocolate and immediately dip in sprinkles or cover in other decoration. Let rest on baking rack or parchment lined baking sheet until chocolate hardens.