### Instructions
1. **Preheat & Prep:** Preheat your oven to 375°F (190°C). Lightly grease an 8×8 inch baking dish with butter or cooking spray.
2. **Combine Dry Ingredients:** In a large bowl, whisk together the rolled oats, baking powder, cinnamon, and salt.
3. **Combine Wet Ingredients:** In a separate medium bowl, whisk together the brown sugar (or maple syrup), melted butter/coconut oil, beaten eggs, milk, and vanilla extract until well combined.
4. **Combine All:** Pour the wet ingredients into the dry ingredients and stir until everything is just moistened. Be careful not to overmix.
5. **Add Berries & Nuts:** Gently fold in the berries and 1/2 cup of the chopped nuts.
6. **Bake:** Pour the mixture into your prepared baking dish and spread evenly. Sprinkle the remaining nuts on top, if desired.
7. **Bake Time:** Bake for 30-35 minutes, or until the oatmeal is set and a light golden brown on top. A toothpick inserted into the center should come out mostly clean.
8. **Cool & Serve:** Remove from the oven and let cool for a few minutes before serving. It firms up as it cools. Serve warm, perhaps with a drizzle of maple syrup or a dollop of yogurt!
### Short Tips
* **Make Ahead:** Bake a batch on Sunday and enjoy it all week! Store individual servings in airtight containers in the refrigerator for up to 4-5 days. Reheat gently in the microwave.
* **Customization:** Feel free to experiment with different fruits (sliced apples, peaches) or spices (nutmeg, cardamom).
* **Protein Boost:** Add a scoop of your favorite protein powder to the wet ingredients for an extra protein punch.
* **Gluten-Free Option:** Ensure you use certified gluten-free rolled oats if you have a gluten sensitivity.
* **Freezing:** Leftovers can be frozen in individual portions for up to 2 months. Thaw in the refrigerator overnight and reheat.
