Preheat the oven to 375˚F and line a 12-cup muffin tray with paper liners.
In a medium sized bowl sift together the flour, baking powder, baking soda, and salt. Stir in the coconut sugar and set aside.
In a small bowl whisk the flax meal and water together until it resembles the texture of a beaten egg. Set aside.
In a large bowl, mix together the milk, yogurt, oil, peanut butter and vanilla extract. Add the flax meal & water mixture and mix until everything is fully incorporated.
Now add the sifted dry ingredients to the wet mixture. Mix gently until evenly mixed.
Scoop 1 ½ tablespoons of the batter into the prepared muffin cases. Tap the muffin tray on the counter top a few times until the batter is level and even.
Spoon ½ to 1 teaspoon of jam onto the center of the batter in the muffin cases. Then scoop the remaining batter mixture over the top of the jam. Its ok if the jam is not completely covered or squeezes out a little.
Bake in the oven for 20 to 25 minutes – or until an inserted wooden skewer comes out clean.
When cooked leave the muffins in the tray for 5 to 10 minutes and then transfer to a wire rack to cool fully.