Method

1. Toast the Oats — Melt 30 g of the butter in a large skillet over medium-high heat. Add the rolled oats and cook, stirring constantly, until they become lightly browned and fragrant. The heat should be high enough to toast the oats rather than steam them, but watch carefully to prevent burning. This takes about 8–10 minutes.
2. Prepare the Pistachios — Chop the pistachios with a knife or pulse them in a blender. Leave small crunchy pieces rather than grinding them into a fine powder.
3. Melt the Remaining Butter — Melt the remaining 70 g butter and let it cool slightly.
4. Mix the Dry Ingredients — In a large bowl, whisk together the sifted flour, baking powder, and cinnamon.
5. Mix the Wet Ingredients — In a separate bowl, whisk together the egg, white sugar, brown sugar, and salt until smooth. Stir in the melted butter.
6. Make the Dough — Pour the wet mixture into the dry ingredients and stir with a spoon or spatula until combined. Do not use a mixer. The dough will seem too soft at first. Add the toasted oats and chopped pistachios, then mix until evenly combined.
7. Shape the Cookies — Preheat the oven to 350°F (180°C) and line a baking sheet with parchment paper. Scoop equal portions of dough onto the baking sheet, leaving plenty of space between them. Roll each portion into a ball by hand if desired, or use an ice cream scoop for evenly sized cookies.
8. Bake — Bake for 14–15 minutes, or until the cookies are lightly golden around the edges.