Stovetop Apple Cinnamon Cake

In a mixing bowl, whisk the egg with the sugar until combined. Add the baking powder and about 130 g of the sifted flour, then stir to start forming a smooth batter.

Pour in the vegetable oil and warm kefir or milk. Add half of the cinnamon and mix until the batter is pourable and mostly lump-free; add the remaining flour only if the batter looks too thin.

Peel the apples if desired, then core and slice them evenly so they cook at the same rate.