Using a stand mixer with the dough hook fitted, mix the flours, sugar, salt, and margarine (or butter). Set aside.
Mix the dry yeast with the warm water and stand for 5-10 minutes until foaming. Add to the dry ingredients and mix until smooth - about 10 minutes with the motor at a medium setting.
Cover the bowl and place somewhere warm for around 45 minutes or until the dough has risen in size.
Knock back the dough and tip out onto a lightly floured surface. Cut into 16 pieces. Flatten a piece between your hands, then place about half a teaspoon of jam onto it and gather the edges of the dough around the jam. Pinch and squeeze the edges to seal in the jam, then roll between your hands to form a ball.
Set aside and repeat with the remaining pieces of dough until you have 16 jam filled balls.
Place the vegetable oil in a shallow bowl, and mix the cinnamon sugar in another bowl.
Roll each ball of dough first in the oil, and then in the cinnamon sugar to coat. Arrange the balls in a 20cm (8inch) round baking tin.
Allow the dough to rise again, for around 30 minutes, or until the balls are doubled in size and there are no gaps between them.
Preheat the oven to 180°C (350°F). Bake the challah for around 25 minutes until it is risen and golden brown.
Remove from the oven and allow to cool for a few minutes before removing from the tin.
Pull apart, eat and enjoy!
Once the challah is assembled in the tin, it can be refrigerated for several hours before baking. However, it will continue to rise (slowly) in the fridge, so keep an eye on it!Approx. per serving: 263 calories, 9.5g fat, 4g protein, 41g carbs