Preheat your oven to 350°F (175°C) and prepare the 8x8 inch square baking pan.

Grate the zucchini and squeeze out excess moisture.

In a large mixing bowl, combine squeezed zucchini, eggs, honey, lemon zest, lemon juice, and almond extract. Whisk until smooth.

In another bowl, whisk together almond flour, gluten-free oat flour, baking soda, and salt.

Toss blueberries in a tablespoon of oat flour and fold into the wet mixture, then combine with dry ingredients.

Pour the batter into the prepared pan and bake for 30-35 minutes or until a toothpick comes out clean.

Cool the cake in the pan for 10 minutes and then transfer to a wire rack.

Prepare the frosting by beating together butter, powdered sugar, lemon juice, and zest until smooth.

Spread the lemon frosting on top of the cooled cake and garnish with fresh blueberries if desired.