Yogurt Cake with Apple and Oats

This one is a bit more substantial, the kind of thing that might be part of a breakfast. The apple makes it nice and moist.

Yogurt Cake with Apple and Oats:

3/4 cup plain yogurt
3/4 cup sugar
3 large eggs
1 cup all purpose flour
1/2 cup quick oats
2 tsps baking powder
spices to taste (cinnamon, cardamon, nutmeg, allspice, cloves...)
1/4 cup vegetable oil
one large apple, peeled and grated

Preheat oven to 350ºF. Butter whatever sort of pan or tin you want to use (like a 9-inch round cake pan which I've never used). In a large bowl, whisk together yogurt and sugar, then whisk in eggs. Add flour, oats, baking powder and spices, mixing just until fully incorporated. Add the oil and mix thoroughly, then add the apple and pour into pan. Sprinkle with sugar. Bake at 350ºF for 30-35 minutes or until lightly golden and toothpick comes out clean. (For mini muffin tins I find 10 minutes does the trick, for regular muffins 20 minutes and for jumbo muffins or mini loaves about 25 minutes, while a whole loaf pan requires more like... 50? I'm not sure, I just keep giving it another five or ten minutes until its done.)

When I made this I threw together a crumble of butter, sugar and oats to put on top, and that was good but a little sweet for me. A lot of it fell off after baking, so if you do that, maybe just put a thin layer on. I'm afraid I have no idea of the quantities I used.