**Preheat the Oven**: Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or grease lightly with oil or butter.

**Mix Dry Ingredients**: In a large bowl, whisk together the flour, sugar, baking powder, salt, and chopped pistachios.

**Combine Wet Ingredients**: In a separate bowl, whisk together the milk, vegetable oil, egg, and vanilla extract. If using optional add-ins like cardamom or food coloring, add them here.

**Combine Wet and Dry Ingredients**: Pour the wet ingredients into the dry ingredients. Gently fold the mixture until just combined. Avoid overmixing. If using white chocolate chips, fold them in now.

**Fill Muffin Tin**: Spoon the batter into the prepared muffin tin, filling each cup about ⅔ full. Sprinkle a few extra chopped pistachios on top for garnish.

**Bake**: Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Rotate the tin halfway through for even baking.

**Cool and Serve**: Remove the muffins from the oven and let them cool in the tin for 5 minutes. Transfer to a wire rack to cool completely before serving.