Preheat the oven to 350 degrees F and line two large baking sheets with silicone baking mats or parchment paper (if you have four large baking sheets line them all, otherwise bake the cookies in two batches).
In a medium bowl whisk together the spelt flour, baking powder and salt. Set aside. In the bowl of a stand mixer with the paddle attachment or in a large bowl with a hand held electric beater, beat the butter until fluffy. Add the peanut butter and vanilla and beat until combined. Scrape down the sides of the bowl. Add both sugars and beat again until well mixed and lighter in colour. Scrape down the sides of bowl again. Add the eggs one at a time, beating to combine in between each addition. Add half of the dry ingredients and mix on low until just combined, then scrape down the sides of bowl one more time. Add the rest of the dry ingredients and mix on low until combined.
Drop 1 1/2 inch spoonfuls of batter onto the cookie sheets two inches apart. Using damp hands roll each spoonful into a ball then use a wet fork to make the crosshatch pattern on top (rinse or wipe the fork off after a couple cookies otherwise it will stick). Bake for 15-18 minutes or until cookies are just barely golden on the edges. Let cool on the baking sheets for five minutes, then transfer to cooling racks to cool completely.
Chop the peanuts or pulse them in a food processor until you have small bits. Arrange all the cookies on parchment lined cookie trays or on another protected surface.
Melt the chocolate and butter in a double boiler until smooth or in the microwave using a microwave safe bowl. Chocolate should run off a spoon with ease, if not add a little additional butter until you achieve the consistency you want. Drizzle the chocolate over each cookie using a small spoon and top with a small amount of peanut bits. Let the chocolate cool and set before storing cookies in an air tight container.