Line a muffin tin with cupcake liners (or lightly grease the openings).
Whisk together the flour, pistachio pudding, salt, and baking powder in a bowl and set aside.
In a large bowl, whisk together the sugar, eggs, vegetable oil, and butter until combined.
Pour in the sour cream, milk, and extracts, and whisk to combine.
Pour the dry ingredients into the wet ingredients and use a rubber spatula to slowly mix and fold the batter together. Be sure to scrape down to the bottom to get any flour that has sunk. Don't over mix - the batter will be quite thick.
Allow the batter to rest while you preheat the oven to 425℉.
Scoop the batter evenly between the liners and top with coarse sugar and chopped pistachios.
Bake at 425℉ for 5 minutes, then reduce the heat to 375℉ and bake for an additional 13-15 minutes. A toothpick inserted into the center will come out with moist crumbs, but no wet batter.
Transfer the tin to a wire rack to cool for 5 minutes, then remove the muffins from the tin to finish cooling.
