Preheat oven to 325°F & Lightly coat an 9x9-in rimmed baking sheet with nonstick cooking spray.
Whisk together flour, oats, brown sugar, cinnamon & baking soda in a large bowl.
In a separate bowl, whisk together butter, apple sauce and milk. Add wet ingredients to flour mixture & stir until crumbly. (Reserve ½ Cup of mixture for later)
Press the rest of mixture evenly into your pan to create the crust.
Whisk yogurt, sugar, 3 Tbsp flour and egg white in a medium bowl. Stir in cranberries.
Pour evenly over the crust & sprinkle reserved oat mixture on top.
Bake until edges are golden brown, 30-35 minutes. Cool completely and slice into bars.