1Preheat your oven to 350°F (175°C). Grease an 8x8 inch baking pan or line it with parchment paper.
In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.
In a large microwave-safe bowl, melt the unsalted butter. Add the peanut butter to the melted butter and stir until smooth.
Add the brown sugar, maple syrup, and vanilla extract to the butter and peanut butter mixture. Stir until well combined.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
Pour the batter into the prepared baking pan and spread it evenly.
Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
Allow the blondies to cool in the pan before cutting into squares and serving.