Preheat the oven to 350 degrees F (180 degrees C).
Wash the strawberries and chop them into small pieces. Add the strawberries to a small saucepan along with the lemon juice and maple syrup. Let it come to a boil, then reduce the heat to medium-low and allow the strawberries to cook down.
After about 5 minutes, once the strawberries soften, use a fork or masher to mash them down. I like to leave a few large chunks in but feel free to mash it as much as you'd like. Add in the chia seeds and stir them in well. Remove the pan from the heat and allow the jam to sit for 10-15 minutes as the chia seeds work to thicken the sauce.
In a separate bowl, whisk together the melted butter, maple syrup, and Greek yogurt until smooth.
Add the oats, oat flour, and baking powder into the bowl with the wet ingredients and mix until well combined into a thick mixture.
Line a loaf pan with parchment paper and add about 3/4 of the oat mixture to the pan. Press this mixture into the bottom of a loaf pan in an even layer.
Pour the strawberry jam mixture on top of the base and smooth it out in an even layer.
Pinch off small pieces of the remaining oat mixture and crumble it on top of the jam. If you would like, sprinkle some extra pieces of granola on top for added flavor and crunch. Use a spatula to lightly press the oat mixture into the jam.
Bake at 350 degrees F for 20 minutes. Allow it to cool completely before slicing it into bars.