Step 1

Preheat the oven to 200C/400F/Gas Line a 12-hole muffin pan with muffin cases, then set aside.

Step 2

Whisk together the flour, baking powder, and salt. Set aside.

Step 3

In a large bowl, whisk together the eggs and sugar until thick and light in colour. Add the buttermilk, oil, vanilla, and peanut butter, and whisk until combined.

Step 4

Add the dry ingredients in thirds and fold in until just combined - do not overmix.

Step 5

Spoon the batter into the muffin cases, filling only halfway. Add about 1 teaspoon of jam to the centres, then top with the remaining batter, filling to the tops.

Step 6

Add a little more jam on the tops of the muffins, and create swirls by running a knife or toothpick through it (microwave the jam beforehand to make it easier to swirl into the batter).

Step 7

Bake for 15 - 20 minutes, or until a toothpick inserted into the centre comes out clean.

Step 8

Allow to cool for 5 - 10 minutes in the pan before transferring them to a wire rack to cool completely.