Preheat your oven to 180c/160c fan/350f/gas mark 4.
Fill a 12 hole muffin tray with muffin or cupcake cases.
Make your milkshake up by mixing your oat milk and milkshake powder in a jug, then add the vinegar, mix and set aside.
In a mixing bowl add your flour, milkshake powder, salt, sugar, and baking powder.
Add the oil to the buttermilk and mix, then pour it into the dry ingredients and fold in. Do not overmix! Only fold until just combined. don't worry about the odd bit of flour mixed in.
Use an ice cream scoop (or spoon) to half fill the muffin cases.
Add ½ teaspoon of jam to the middle of each case of batter, then top with more batter until the cases are about ¾ full.
Bake for 20-25 minutes until risen and baked through. Use a skewer to see if they are ready. Tips in the notes below.
Remove from the oven, leaving the muffins in the tray for a few minutes, before moving them to a baking rack to cool completely.
Enjoy!
Notes
Use a skewer or toothpick to see if they are ready. Insert it into a muffin, if it comes out clean they are ready, if there is batter on it they need a little longer.
The muffins can be kept in an airtight container for 3 days. If you pop the box in the fridge when they are cool, you will get another couple of days out of them.
The muffins can be frozen in a freezer bag for up to 3 months. Defrost at room temperature.