Ingredients:

  • 1 ½ cups Quick Cooking Oats (150 grams)
  • ½ cup All-Purpose Flour (60 grams)
  • ½ cup packed Light Brown Sugar (100 grams)
  • 1 teaspoon Ground Cinnamon
  • ½ teaspoon Fine Sea Salt
  • ¼ teaspoon Baking Powder (Optional)
  • ½ cup (1 stick) Unsalted Butter, melted and slightly cooled (113 grams)
  • 1 teaspoon Vanilla Extract

Instructions:

  1. Preheat your oven to 350°F / 175°C / Gas Mark 4. Lightly grease the interior of the 9-inch pie dish.
  2. For a finer crust, pulse 1 cup of the quick oats in a food processor until they resemble coarse flour. Leave the remaining ½ cup whole. If you don’t have a processor, use quick oats exclusively.
  3. In the large bowl, whisk together the processed oats, whole oats, flour, brown sugar, cinnamon, salt, and baking powder (if using). Ensure there are no lumps of sugar.
  4. Pour the melted butter and vanilla extract into the dry mixture. Stir well with a spatula until the mixture is evenly moistened and resembles damp, coarse sand. The mixture should hold its shape when squeezed.
  5. Transfer the mixture into the prepared pie dish. Start by pressing the crumbs firmly up the sides of the dish, creating an even edge. Then, press the remaining crumbs into the base.
  6. Use the bottom of a flat-bottomed measuring cup or glass to compact the entire crust—sides and base. Pressure is key here; you want a dense, proper foundation.
  7. Place the pie dish in the refrigerator for at least 30 minutes. Chilling solidifies the butter, preventing the crust from shrinking or slumping in the oven.
  8. Transfer the chilled crust directly into the preheated oven. Bake for 12–15 minutes, or until the edges are lightly golden brown and the crust smells distinctly of toasted oatmeal cookies.
  9. Remove the crust from the oven and place it on a wire rack. Allow it to cool completely to room temperature before adding any filling.