To begin, set your oven to 375°F (190°C) so it's all set when you’re ready to bake. Take your muffin tin and place paper liners in each cup.
In a large mixing bowl, combine the flour, sugar, baking powder, salt, and pistachio pudding mix by whisking them together.
Next, in another bowl, whisk together the milk, sour cream, eggs, melted butter, oil, and vanilla extract. Keep going until the mixture is smooth.
Pour the wet ingredients into your dry ingredients and gently fold everything together.
Use either a spatula or a wooden spoon. Take it easy while mixing, you don’t want to overdo it!
Use a spoon to fill your muffin tin with batter, then sprinkle chopped pistachios on top of each muffin. This not only makes them look fancy but also adds a delightful crunch.
Bake your muffins for 20 minutes. Watch closely as they bake, the tops should be firm, lightly golden, and a toothpick inserted in the center should come out clean.
Allow the muffins to cool in the tin for around 5 minutes, then move them to a wire rack to cool down fully.