Preheat the oven to 350°F. Line a 8 x 8-inch baking pan with parchment paper and set aside.
In a large mixing bowl whisk together the melted butter and brown sugar. Add the egg and egg yolk, and vanilla extract and mix well.
Add the flour, ground cinnamon, baking powder, and salt and use a rubber spatula to fold together until just mixed and no streaks of flour remain.
Add the old fashioned oats, shredded coconut, chocolate chips, and chopped pecans and fold into the batter until evenly distributed. Do not over mix.
Transfer the batter into your prepared pan, spreading it evenly to the edges.
Bake for 25 to 30 minutes or until the cookie bars are golden brown, set on the edges and have puffed up. The middle will still be slightly undercooked, but they will continue to cook as they cool!
Once the bars are cool, cut into 9 squares for big blondies, or 16 squares for smaller portions and enjoy!