Ingredients:

  • 2 cups Rolled Oats (Old-Fashioned)
  • 1/3 cup packed Light Brown Sugar
  • 1 tsp Baking Powder
  • 1 tsp Ground Cinnamon (for the base)
  • 1/2 tsp Fine Sea Salt
  • 2 Large Eggs
  • 1 1/2 cups Milk (Whole or 2%)
  • 1/4 cup Unsalted Butter (melted and cooled slightly)
  • 1 tsp Pure Vanilla Extract
  • 2 tbsp Granulated Sugar (for the swirl)
  • 1/2 tsp Ground Cinnamon (for the swirl)
  • 1 tbsp Unsalted Butter (very soft, room temperature, for the swirl)

Instructions:

  1. Preheat the oven to 375°F (190°C). Lightly grease an 8x8 or 9x9 inch baking dish.
  2. Combine Dry Ingredients: In a large mixing bowl, whisk together the rolled oats, brown sugar, baking powder, 1 tsp cinnamon, and salt. Set aside.
  3. Combine Wet Ingredients: In a separate bowl, whisk together the two large eggs, milk, melted butter, and vanilla extract until fully incorporated.
  4. Marry the Mixtures: Pour the wet mixture over the dry ingredients. Stir just until the ingredients are combined and the oats are moistened. Do not overmix.
  5. Pour the oatmeal base mixture evenly into the prepared baking dish.
  6. In a small bowl, combine the 2 tbsp granulated sugar, 1/2 tsp cinnamon, and the 1 tbsp of very soft butter. Mix thoroughly with a fork until a thick, uniform paste forms.
  7. Drop small, teaspoon-sized dollops of the cinnamon-sugar paste evenly over the top of the oatmeal mixture in the dish.
  8. Using the tip of a knife or a skewer, gently drag through the dollops, creating a marbled pattern on the surface of the oatmeal.
  9. Place the dish in the preheated oven and bake for 30 to 35 minutes, or until the edges are golden brown and the center is set.
  10. Remove from the oven and allow to rest for at least 10 minutes on a wire rack before slicing and serving. This resting time is crucial for structure.