Preheat oven to 375-degrees Fahrenheit (190 degrees Celsius).
In a large mixing bowl, cream together 8 tablespoons of butter along with 1 cup of granulated sugar.
Add 2 large eggs and 1½ teaspoon pure vanilla extract. Blend until creamy.
Add 1 cup ricotta cheese to the mixture and blend to combine.
In a large bowl whisk together the flour baking powder, and salt.
Add half the flour mixture to the butter/sugar mixture and blend.
Add the remaining flour mixture to the batter and blend until combined.
Add the lemon zest, shredded (dried) zucchini, and blueberries to the batter and stir gently with a spatula to combine.
Use a medium cookie scoop or two tablespoons to drop the cookie batter onto parchment-lined baking sheets, leaving plenty of space between the cookies. I did 8 cookies per baking sheet.
Bake the cookies for a total of 22-24 minutes, rotating the cookie sheets halfway through the baking process.
Remove to cooling racks to cool completely before frosting, or dusting with confectioners sugar.
To make the lemon drizzle:
Combine all the ingredients in a large bowl and blend with a hand mixer until you reach your desired drizzle consistency.
Add more liquid for a thinner drizzle, and add more confectioners sugar for a thicker drizzle.
Drizzle over cookies by using a piping bag, or spoon a light drizzle over the cooled cookies.
Notes
If desired sprinkle cooled cookies with confectioners sugar instead of the lemon buttercream drizzle.Store cookies in an airtight container in the refrigerator for up to 5 days.Cookies may be frozen. Store in an airtight freezer container and freeze for up to 3 months.