Preheat the oven to 350°F (175°C) and grease an 8-inch baking pan or line with parchment paper.

In a large bowl, combine oats, flour, cinnamon, salt, baking powder, and sugar.

Add oil or melted butter to the dry mixture and stir until crumbly. Press two-thirds into the bottom of the pan.

In a separate bowl, mix strawberries, cornstarch, and maple syrup. Spread over the oat base.

Crumble the remaining oat mixture over the strawberry filling.

Bake for around 45 minutes until golden brown and firm in the center.

Let the bars cool for about 30 minutes, then refrigerate for at least 2 hours to firm up.

Slice into squares or rectangles and serve.