Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan.

In a stand mixer, beat the softened unsalted butter and 1 cup of granulated sugar together on medium speed for about 3-5 minutes, or until light and fluffy.

Add the eggs, one at a time, mixing well after each addition, then add the 2 teaspoons of vanilla extract and mix until fully combined.

In a food processor, combine the fresh cranberries and 1 tablespoon of sugar, pulsing until roughly chopped. Add to the butter mixture, mixing just until incorporated.

In a separate bowl, whisk together the flour, baking powder, salt, and pistachio pudding mix until blended.

Gradually add half of the dry mixture to the wet batter, mixing gently; then pour in the 1/2 cup of milk and mix until integrated.

Add the remaining dry mixture and 1/4 cup chopped pistachios, folding carefully until no dry streaks remain.

Pour the batter into the prepared loaf pan and smooth the top evenly.

Bake for 55-65 minutes, checking for doneness with a toothpick. It should come out clean when inserted into the center.

Once baked, let the bread cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.