Preheat oven to 350 degrees F (175 degrees C). Line bottom of 9-inch square baking pan with foil. Lightly coat with cooking spray.

In a food processor, pulse together 1 1/2 cups of flour, 1 cup of oats, 3/4 cup of pecans, 3/4 cup of white sugar, 1/2 cup of shredded coconut, 1/4 cup of brown sugar, and 1 teaspoon of salt until blended. Add butter and pulse until well blended. This is the crust.

Put 4 1/2 cups of mixture into the prepared pan. Press into an even layer. Transfer remainder to a small bowl; using your hands, squeeze and rub mixture together until crumbly. This is the streusel. Add streusel to second baking sheet.

Bake both, stirring streusel halfway through, until streusel is golden, about 18 minutes. Remove streusel from oven. Bake crust until golden brown, about 12 minutes more.

Microwave 1 cup of chocolate chips and 1/2 cup of peanut butter in microwave-safe bowl on High in 30-second intervals, stirring after each interval, until mixture is melted and fully combined. This is the filling.

Pour chocolate mixture over baked crust. Sprinkle with streusel. Chill until set, 2 to 3 hours. Cut into 20 bars.