Preheat oven to 350°F. Line an 8x8 square baking pan with parchment paper. Prepare the topping by mixing together the cinnamon and sugar in a small bowl. Set aside.
1 tablespoon sugar, 1 teaspoon cinnamon
In a large bowl, mix the sugar, oil, yogurt, and vanilla extract together. Add in the flour, baking powder, cinnamon, and salt and mix until incorporated.
¾ cup sugar, ⅓ cup vegetable or canola oil, ⅓ cup Greek yogurt, 1 teaspoon vanilla extract, 1 cup flour*, ½ teaspoon baking powder, ½ teaspoon cinnamon, ¼ teaspoon salt
Transfer the batter into the pan. Sprinkle the cinnamon sugar mixture evenly on top. Bake for 15-18 minutes. Allow to cool in the pan completely before cutting into bars.
Notes
Although I use a gluten free flour, you can use AP flour without having to make any adjustments to the recipe.