Dice the peeled and cored Granny Smith apple into small pieces. Squeeze a small amount of lemon juice over the apple and gently toss to help prevent browning.
Weigh or measure the white sugar and light brown sugar into a bowl and set it aside. In a separate bowl, weigh or measure the flour, baking powder, kosher salt, and cinnamon. Whisk to blend.
Cube the room-temperature butter into a mixer bowl and cream on medium speed for 1 to 2 minutes. Add both sugars and mix on medium speed for 3 minutes. Scrape down the sides of the bowl and mix for another 30 seconds.
Add the egg and apple juice, mixing until incorporated. With the mixer on low speed, add the flour mixture about one-third at a time. Mix just until incorporated.
Scrape down the bowl, then add the diced apple and chopped peanuts. Mix on low just until distributed throughout the dough. Finish mixing with a spatula if needed.
Add the cut-up Granny Smith apples and the chopped peanuts. Turn the mixer on medium-low and blend for about 30 to 45 seconds. You may have to hand mix a little to get the apples and peanuts throughout the whole dough. Then, stick the mixing bowl into the refrigerator for half an hour.
Cover the mixer bowl and refrigerate the cookie dough for 30 minutes.
Preheat the oven to 350°F (175°C or 180°C) and line two sheet pans with parchment paper. Using a medium cookie scoop, place 12 mounds of dough on each pan.
Bake for 10 to 12 minutes. Let the cookies rest on the pan for 1 to 2 minutes before moving them to a wire cooling rack.