Preheat your oven to 350°F (175°C) and prepare your jelly roll pan by greasing it thoroughly.

In a bowl, mix together oil, white sugar, brown sugar, eggs, and vanilla extract until smooth.

Add all-purpose flour, oats, baking powder, salt, and ground cinnamon; stir gently until just combined.

Fold in the shredded zucchini until evenly distributed in the batter.

Pour the batter into the greased jelly roll pan and spread evenly with an offset spatula.

Bake for 18-22 minutes until a toothpick inserted comes out clean.

Allow the bars to cool completely in the pan on a wire rack for about 30-45 minutes.

To make the frosting, beat the cream cheese and butter until fluffy, then add powdered sugar and mix until smooth.

Spread the frosting over the cooled bars and cut into squares or rectangles to serve.