Preheat your oven to 400°F (204°C) and line a baking sheet with parchment paper.

In a large mixing bowl, combine the dry ingredients: flour, salt, baking powder, baking soda, and sugar.

Cut the cold, cubed butter into the flour mixture until it resembles coarse crumbs.

Whisk together the beaten egg and sour cream in a small bowl, then pour into the dry mixture and stir until just combined.

Toss the drained zucchini and cheese with the remaining flour, then fold into the dough.

Transfer the dough onto a floured surface and press into an 8-inch circle. Cut into 8 wedges.

Place the scone wedges on the prepared baking sheet and sprinkle with the remaining cheddar.

Bake for 22-24 minutes or until golden brown and a toothpick inserted comes out clean.

Let the scones cool slightly before serving warm.