Combine the flour, baking soda and salt. Set aside.
Cream together the butter and peanut butter in a mixing bowl. Add brown sugar and mix well. Add in the eggs, one at a time beating after each one. Add in the vanilla and mix well.
Slowly add in the dry ingredients on low speed. Mix until ingredients are combined, scraping the sides of the bowl down.
Chill at least an hour or overnight.
Preheat oven to 350 degrees and cover your cookie sheet with parchment paper or silicone mat.
Make dough balls about one tablespoon in size. Pour some brown sugar in a small bowl. Roll each dough ball in the brown sugar and place them on your prepared cookie sheet. Space the cookies about two inches apart.
Bake for eight minutes. Remove from the oven and gently press a kiss in the middle of each cookie. Place back in the oven and bake for an additional two minutes.
Let the cookies cool on a cooling rack.
Let them cool completely.
For adding the melted chocolate over finished cookies: If adding the melted chocolate, break apart the Baker's chocolate pieces and place in a microwave safe bowl. Heat for 30 seconds and stir. If chocolate is not completely melted, repeat at 10 second increments, stirring after each one, until the chocolate is completely melted.
Line the cookies up on parchment paper. Pour the chocolate into a frosting bag with a fine tip or a plastic sandwich bag and cut the corner off slightly. Drizzle the cookies with the melted chocolate by going back and forth over the cookies until the desired amount of chocolate is on the cookies.
Let them sit until the chocolate sets.
Store in an airtight container.