In a medium bowl, combine and whisk all-purpose flour,baking powder, baking soda (bicarbonate of soda), salt and ground cinnamon.
2 cups (240 g) all purpose flour, 1 teaspoon (4 g) baking powder, ¼ teaspoon (1 g) baking soda (bicarbonate of soda), ½ teaspoon salt, 1 teaspoon ground cinnamon
In a separate large bowl, beat together with white granulated sugar with an electric mixer on high speed.
2 large eggs, 1 cup (200 g) white granulated sugar
Ensure that you continue beating for 4 - 5 minutes or until the mixture is pale in color.
Add plain unflavored yogurt or sour cream, vegetable oil and vanilla extract. Beat on low speed until just combined, about 30 seconds.
1 cup (240 ml) plain unflavored yogurt or sour cream, ½ cup (120 ml) vegetable oil
Add the flour mixture, ⅓ at a time, beating on low speed with each addition just until combined. Do not overmix or cupcakes will turn out dense. You can also use handheld whisk or spatula to mix in the flour.
Gently mix the chopped apples into the batter until evenly distributed.
¾ pound (340g) apples, peeled, cored and chopped
If using a 12 cavity brownie pan: Fill each cavity about halfway with the batter. Bake for 18 - 22 minutes or until the tops are golden and a toothpick inserted into the center comes out clean.
If using a 9 inch (23 cm) pan: Pour the mixture into the lined baking pan. Bake for 20 - 25 minutes or until the top is golden and a toothpick inserted into the center comes out clean.
Leave in the pan for 5 minutes, then turn out onto a cooling rack to cool completely.