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

In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, brown sugar, baking soda, baking powder, salt, and ground cinnamon until well combined.

In a separate bowl, whisk the melted unsalted butter, pure maple syrup, milk, large egg, and vanilla extract until smooth and well blended.

Gently pour the wet mixture into the bowl with the dry ingredients, folding them together with a spatula until just combined.

Carefully pour the batter into the prepared baking pan, using a spatula to spread it out evenly.

Place the pan in the preheated oven and bake for 20 to 25 minutes until edges are golden brown.

Once baked, remove the pan from the oven and let the bars cool in the pan for about 10 minutes.