Bowl 1: Bring the butter to room temperature and knead the sugar into it a third at a time until it becomes creamy. This takes about 2~3 minutes with an electric mixer. Preheat the oven to 180℃.
Add the peanut butter and mix. Mix in the egg and vanilla.
Bowl 2: Thoroughly mix together the dry ingredients.
Divide the dry ingredients into 3 portions and mix in one portion at a time into Bowl 1 until there are no flour streaks.
Bowl 3: If you're using a chocolate bar, break it up. Chop up the peanuts into your desired size. Add to Bowl 1.
Make 3-3.5 cm balls with the dough. If the dough is hard to bring together, wrap the bowl with plastic wrap and chill in the refrigerator for 30 minutes.
Line the baking sheet with kitchen parchment paper and arrange the dough balls on top. Use your fingers to squish the balls into discs.
Bake at 180℃ for 10 minutes. Midway through, flip the cookies over. The cookies may not appear to be completely baked.
The cookies are soft and break easily, so let cool on the parchment paper for about 3 minutes before removing. You can leave the parchment paper on the baking sheet.
They will harden up nicely when cooled, so don't worry. Over-baking will ruin the texture.
I used Skippy's creamy peanut butter. The crunchy type would also be delicious.
I replaced the chocolate and peanuts with crushed peanut M&Ms (two 50 g bags). Easy and delicious!
I made slightly thicker, 5 cm cookies like the Country Ma'am brand. It made 38 cookies. They'd be great as a gift!
Story Behind this Recipe
I made some peanut butter cookies for a peanut butter-loving friend by referencing a foreign recipe site. I made it many times, adjusting the combination of ingredients, until I came up with just the right balance that everyone loves.
The corn starch gives it a great, crunchy texture. It's soft and fluffy when just baked (so soft, you won't be able to move them around). That's why you should be sure to let it cool on the paper before handling them. If they break apart while they're still warm, you can try forming them back together again and rearranging the shapes. If you let it sit for a day, the flavors will settle.