Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 9x13-inch baking pan with cooking spray.
Combine canola oil and 1/2 cup chocolate chips in a saucepan over very low heat; stir until melted, about 5 minutes. Let cool, about 5 minutes.
Beat sugar, eggs, and vanilla extract in a large bowl until blended. Fold in melted chocolate mixture. Sift in flour, baking powder, and salt; mix until well combined. Fold 1 1/2 cup shredded coconut and chocolate chips into the batter.
Spread batter in the prepared baking pan. Sprinkle remaining 1/2 cup shredded coconut on top.
Bake in the preheated oven until edges pull away from the sides of the pan, 35 to 40 minutes. Cool before cutting into squares, about 15 minutes.