Preheat the oven to 350°F (180°C) and butter and line with parchment a 9x5-inch (12½x 25½-cm) loaf pan. Set aside.

Place the blueberries in a small bowl and toss with the tablespoon of flour. Set aside.

In another bowl, mix the remaining cup flour together with the baking powder and salt. Set aside.

In the bowl of a stand mixer fitted with a paddle attachment or with a medium bowl and handheld electric mixer, beat the butter, cream cheese, sugar, and lemon zest together on medium-high until it is light and fluffy, about 3 minutes.

Add the vanilla extract, then the eggs, one at a time.

Fold in the dry ingredients until just combined, then mix in the blueberries.

Scrape into the prepared pan and bake for about 65 minutes, until the top is golden brown and a skewer inserted in the center comes out clean.

Let cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

Store in an airtight container at room temperature for up to 2 days.