Set baking pan on a baking sheet, and bake for 40-50 minutes, or until a wooden toothpick comes out clean.
Cool completely, and dust with powdered sugar just before serving, if desired.
Powdered sugar
Notes
Greek yogurt: Sour cream could be used in place of the Greek yogurt. I don't recommend using fat-free sour cream.
The blueberries sink to the bottom of this coffee cake and form a nice sweet layer along the bottom. If you want the keep the berries from sinking, toss them with a tablespoon or so of flour before you fold the blueberries into the batter.