Preheat the oven to 350°F (180°C). Have ready a 12 muffin pan with paper liners.
Sift the dry ingredients together: 1 cup all-purpose flour, 1 ½ teaspoons baking powder½ teaspoon cinnamon and ¼ teaspoon salt in a large mixing bowl. Add 1 cup quick or instant oats and stir to mix.
In a medium bowl, combine 1 cup ripe mashed bananas, ⅓ cup plain Greek yogurt, ¼ cup vegetable oil, 2 eggs and 1 teaspoon vanilla extract. Add ½ cup sugar and ¼ cup light brown sugar and stir in well with a spatula or a hand whisk. Don't beat, simply integrate.
Toss 1 cup fresh blueberries gently into the flour mixture to coat them; this prevents them from sinking during baking.
Add the wet ingredients into the dry ones all at once and stir or fold both preparations lightly until combined, but don’t overdo it or the muffins will lose some of their softness.
Divide the muffin batter into the prepared muffin tins, filling them ¾ of their capacity.
Bake for 20-25 minutes, until the muffins are golden on top and a toothpick or cake tester inserted in the center comes out clean.
Remove from the oven, let cool for a few minutes on a wire rack and remove from the pan. Let cool completery on the cooking rack. Eat warm, or at room temperature.