Preheat the oven to 350 degrees Fahrenheit and line a 9×9 baking dish with parchment paper.
To brown the butter, heat a small saucepan over medium-low heat and add the butter. Let it melt, then simmer gently for about 5 minutes, swirling the pan often, until the butter is golden brown and smells nutty.
In a medium bowl, whisk together the butter, brown sugar, and maple syrup until well combined. Mix in the eggs and vanilla. Fold in the shredded apple.
In a separate bowl, mix together the flour, baking powder, and salt. Add the dry ingredients into the wet ingredients and fold until just combined. Do not over mix!
Pour the batter into the lined baking dish and place in a preheated oven. Bake for 30-35 minutes, until a toothpick inserted into the center comes out clean. Allow to cool before removing and serving.
To make the maple caramel, heat a small saucepan over low heat. Add the butter. Once the butter is melted, add the brown sugar and maple syrup. Stir to dissolve the sugar and bring to a low simmer. Let simmer for 5 minutes or until slightly thickened. Remove from the heat and let sit for 5 minutes before drizzling on top of the blondies.
Substitute 1:1 all-purpose gluten-free flour for the regular four for a gluten-free version.