Preheat your oven to 375 degrees Fahrenheit. Spray a 9x13 inch baking dish with nonstick spray and set aside.
In a large mixing bowl, beat together the 3/4 cup butter and 1 1/2 cups granulated sugar, until fluffy 1-2 min.
Add the eggs and extracts, and mix until combined.
In a separate bowl, whisk together the flour, baking powder, salt, and lemon zest.
Add 1 tbsp. of lemon juice to the milk, and alternate adding the flour mixture and the milk to the butter mixture, mixing in between additions.
Once the batter is combined, carefully fold in the blueberries.
Bake at 375 for 30-35 minutes.
Meanwhile, add the remaining 1/4 cup lemon juice and 1/4 cup sugar to a medium saucepan. Heat until steamy, whisking until the sugar is dissolved. Remove from the heat.
Once the cake has finished baking, use a toothpick to poke holes throughout the top of the cake.
Drizzle the lemon juice and sugar mixture over top.
Allow the cake to cool completely.
Use the 8 ounce of cool whip to frost the cake.
Top each piece with extra fresh lemon slices or blueberries, optional.