Preheat oven to 375F. In a medium bowl, combine the dry ingredients; the cups of the flour, sugar, salt, baking powder and fresh lemon zest. Set aside.
In a large mixing bowl combine the wet ingredients. Add your buttermilk, lemon juice, melted butter, and vanilla extract. Mix to combine.
Add half of the flour mixture to the wet ingredients and mix at low speed, or use a wisk. Then add the rest of the dry ingredients to your large bowl and mix until flour is fully incorporated.
Gently fold in your blueberries and chopped mint.
Pour cake batter into your prepared pan.
Bake in the oven for about 1 hour, or until the middle of the cake comes out clean with a cake tester.
Allow to cool for 10-15 minute on a wire rack before attempting to slice or remove for the baking pan.