Preheat oven to 350°. Spray a standard muffin tin with non stick spray. Set aside.
In a large mixing bowl, whisk together the flour, instant pudding mix, baking powder, and salt. Set aside.
In another bowl, with an electric mixer, mix together the oil, buttermilk, sugar, eggs, and vanilla extract until light and creamy.
Pour dry ingredients into wet ingredients and mix until just combined. With a spatula, fold in chopped pistachios.
Transfer batter to muffin tin. Bake for 18-20 minutes or until a toothpick inserted into the center of the muffin comes out clean.
Leave the muffins in the pan to cool down for 10 minutes. With a knife, loosen the edges and then transfer muffins to wire rack to cool completely.
Once cooled, drizzle honey over each muffin. Store muffins in an airtight container for 2-5 days.