Preheat the oven to 350F and line an 8x8 square pan with parchment paper.
To a small bowl, add the flour, baking powder and cinnamon; whisk to combine and set the bowl aside.
To a medium bowl, add the sugar and orange zest. Rub the zest into the sugar using your fingers until the zest is incorporated through out the sugar.
Add the melted butter to the sugar and zest. Whisk until all ingredients are well incorporated and it has a smooth, whipped texture - about a minute.
Add the yogurt and vanilla extract; whisking until well incorporated- about 30 seconds.
Add the dry ingredients to the wet ingredients, whisking just until no more flour can be seen.
Pour the batter into the prepared pan and bake for 28 to 32 minutes. The edges should be starting to brown and pulling away from the pan. A toothpick inserted should come out clean.
Allow the blondies to cool completely in the pan. Once cooled, the blondies can be glazed and served.