1Preheat oven to 350°F. Butter a 9 x 5 loaf pan. Line the bottom of the pan with parchment paper and butter the parchment paper as well. Set aside.
In a medium bowl, whisk together flour, baking powder and salt. Set aside.
In stand mixer, beat together cream cheese, butter and sugar until light and fluffy, about 2 minutes. Add eggs one at a time, thoroughly mixing each time. Add vanilla extract and lime zest, mixing until combined.
Pour flour mixture over the batter mixture. Using a large rubber spatula, gently fold in the flour until it’s completely mixed in and there are no pockets of dry flour. Lastly, gently fold in the blueberries.
Transfer batter to prepared baking loaf pan. Bake for 55-65 minutes, or until toothpick inserted in the center comes out clean. Let sit until cool, at least 30 minutes and then remove from pan.
In a stand mixer or large bowl, cream butter and cream cheese until smooth. Add confectioners' sugar and beat on low speed until combined, then on high until frosting is smooth. Beat in vanilla extract.
Carefully frost on top of the cooled pound cake and store in fridge until ready to serve.