Preheat the Oven: Set it to 350°F (175°C). Grease an 8×8-inch baking dish or line it with parchment paper.

Mix Dry Ingredients: In a large bowl, combine the rolled oats, baking powder, ground cinnamon, and salt. Stir until blended.

Whisk Wet Ingredients: In another bowl, mix together the almond milk, Greek yogurt, honey or maple syrup, vanilla extract, and eggs until smooth.

Combine Wet and Dry: Add the wet ingredients to the dry mixture and stir gently until just combined.

Incorporate Protein: Stir in the vanilla protein powder until well mixed.

Melt and Mix: Pour in the melted coconut oil or butter and stir until fully incorporated.

Add Optional Ingredients: If desired, fold in the raisins and chopped walnuts for added texture.

Spread and Bake: Pour the mixture into the baking dish, spreading it evenly with a spatula. Bake for 35-40 minutes, or until the edges are golden brown and the center is set.

Cool and Slice: Let it cool for 10 minutes before slicing into squares.