Prepare: Preheat your oven to 200°C (392°F) and line 2 muffin trays with 10-12 muffin liners - leave a gap between each one as you will only be filling every second cavity.

Make the streusel topping: To a medium bowl, add the flour, sugar, cinnamon, and butter. Use your fingertips to rub the butter into the dry ingredients. You'll be left with a crumble consistency. Set aside in the fridge.

Cinnamon sugar: In a small bowl, combine the brown sugar and cinnamon and set aside.

Make the muffin batter: To make the vegan "buttermilk" add the soy milk and apple cider vinegar to a medium bowl, stir, and allow to sit for 5 minutes.Add the olive oil, yogurt, brown sugar, and vanilla extract to a medium bowl and whisk to combine. Whisk in the vegan buttermilk.To a separate large bowl, add the flour, baking powder, baking soda, cinnamon, and sea salt. Whisk to combine.

Sift the dry ingredients into the wet ingredients in 2 parts. Fold the ingredients into the batter between each increment until there are no pockets or streaks of flour. Do not be tempted to overmix!

Line half of the cavities in the muffin tray with muffin liners - I recommend only filling every second cavity as this promotes high muffin tops! The recipe will make 8 large muffins - so if you only have one muffin pan I recommend baking them in 2 batches, just make sure you let the pan cool between batches, and keep the muffin batter rested in the fridge until ready to use for the second batch.

Using an ice cream scoop or large spoon, distribute half of the batter amongst the muffin liners, filling them halfway. Sprinkle the cinnamon sugar on top of each muffin in an even layer.Fill each muffin case with the remaining muffin batter and sprinkle the cinnamon streusel on top.

Bake at 200°C (392°F) for the first 5 mins, then turn down the temperature to 175°C (347°F) and bake for another 15 minutes. Check they are done by piercing them with a toothpick or a knife, the knife should come out almost clean- a few crumbs are fine. Allow the muffins to cool for 5 minutes, then carefully lift them out of the tray and transfer them to a cooling rack to cool further for 30 minutes.

Make the glaze: Mix together the powdered sugar, vanilla extract, and non-dairy milk until smooth. You can add more or less sugar depending on whether you want it runny or thicker. Drizzle the icing on top of the muffins once they have cooled.

Storage: Place the muffins in an airtight container and store them at room temperature for up to 5 days or in the fridge for up to a week. Let them sit at room temperature for an hour before serving if stored in the fridge. You can freeze them in an airtight container and defrost them for a couple of hours before serving.You can also gently warm the muffins in the oven to get them back to tasting like they're been freshly baked!