Step 1: Preheat the Oven

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan or line it with parchment paper.

Step 2: Mix Dry Ingredients

1. Combine Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.

Step 3: Cream Butter and Sugar

1. Cream Butter and Sugar: In a large bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3–5 minutes.
2. Add Eggs and Vanilla: Beat in the eggs one at a time, then stir in the vanilla extract.

Step 4: Combine Wet and Dry Ingredients

1. Mix in Buttermilk: Gradually add the buttermilk to the butter mixture, mixing until just combined.
2. Add Dry Ingredients: Slowly add the dry ingredients to the wet ingredients, mixing gently until just combined. Be careful not to overmix.

Step 5: Fold in Cranberries and Pistachios

1. Fold in Add-ins: Gently fold in the chopped cranberries, pistachios, and orange zest (if using) until evenly distributed throughout the batter.

Step 6: Bake

1. Pour Batter: Pour the batter into the prepared loaf pan and smooth the top with a spatula.
2. Bake: Bake in the preheated oven for 55–60 minutes, or until a toothpick inserted into the center comes out clean.

Step 7: Cool and Serve

1. Cool: Remove the bread from the oven and let it cool in the pan for about 10 minutes. Then transfer it to a wire rack to cool completely.
2. Slice and Serve: Once cooled, slice and serve the bread. It can be enjoyed plain or with butter.