Place buttermilk in the freezer for 15 minutes.
Heat oven to 350F and line a muffin tin with parchment paper or muffin liners.
In a medium bowl add flour, sugar, baking powder, and salt, mixing to combine.
Melt butter over medium heat and once melted cut from the heat.
Remove buttermilk from the freezer and pour melted butter on top, let butter sit for about 30 seconds and then whisk with a fork.
Add egg to buttermilk mixture and whisk to combine, about a minute.
Using a spatula, fold the buttermilk mixture into the dry ingredients until no white streaks of flour are visible.
Add about a ¼ cup of the batter to the bottom of each muffin well and then using the back of a greased spoon, create an indentation.
Add about a teaspoon of jam to each indentation.
Spoon tablespoons of the remaining batter over the jam, it doesn't need to cover the jam perfectly or be smooth.
Heavily sprinkle turbinado sugar over the top of each muffin.
Bake for 30-35 minutes until a toothpick inserted comes out clean and the tops are golden brown.
Let the muffins cool for 10 minutes before enjoying.
