Step 1

Preheat oven to 425℉ (220℃) conventional (see note 2 if using a convection oven) and line a 12-hole standard muffin tray with muffin liners. Set aside.

Step 2

Sift together flour, cornstarch, baking powder, baking soda, salt and cinnamon. Whisk until well combined. Set aside.

Step 3

In a large bowl combine hot milk and oats. Stir to combine and allow to sit for 10 minutes (see note 3). In the meantime prepare the streusel.

Step 4

Streusel: In a small bowl combine flour, light brown sugar, oats, cinnamon and salt. Mix until well combined and no large lumps remain. Add in melted unsalted butter and stir until the mixture becomes crumbly yet slightly moist (see note 4 if it's too dry or too wet). Set aside.

Step 5

Return to the milk/oat mixture and add in light brown sugar, unflavored vegetable oil, eggs and vanilla. Using a whisk, mix until well combined.

Step 6

Add in pre-sifted dry ingredients from earlier to the wet mixture and using a spatula, fold until just combined and the batter is uniform. Do not overmix.

Step 7

Distribute the batter evenly among the muffin liners, filling each about ¾ full. Avoid overfilling, as this can cause the muffins to overflow during baking. Give the streusel a quick stir, then evenly sprinkle it over the tops of the muffins.

Step 8

Bake for 8 minutes at 425℉ (220℃) and then while the muffins are still in the oven, lower the temperature to 350℉ (180℃) and bake for a further 10-12 minutes, or until a toothpick inserted into the centre comes out clean, or with a few moist crumbs on it.

Step 9

Allow to cool in the muffin tray for 10 minutes, before transferring to a wire rack. Enjoy!