Preheat your oven to 350°F (175°C) and prepare a 9x5 inch loaf pan by greasing it lightly with butter or lining with parchment paper.

In a stand mixer, combine ½ cup softened butter and 1 cup sugar. Mix on medium speed until light and fluffy, about 3-5 minutes.

Add 2 large eggs and 1 teaspoon vanilla extract to the mixture. Beat on medium speed until fully incorporated, around 1-2 minutes.

In a food processor, pulse 1 ¼ cups of fresh cranberries with 1 tablespoon of sugar until roughly chopped.

In a separate bowl, sift together 2 cups all-purpose flour, 1 ½ teaspoons baking powder, ½ teaspoon salt, and the pistachio pudding mix.

Gradually add half of the dry mixture to the wet ingredients on low speed, mixing gently until just incorporated.

Pour in ½ cup of milk and mix again until smooth. Add the remaining dry mixture and ½ cup chopped pistachios, mixing until just combined.

Pour the batter into your prepared loaf pan, smoothing the top evenly and filling it about ¾ full.

Bake in the preheated oven for 55-65 minutes, until the top is golden brown and a toothpick comes out clean.

Let the loaf cool in the pan for about 10 minutes before transferring to a cooling rack to cool completely.