Preheat the oven to 375°F (190°C) and line an 8"x8" (22cmx22cm) baking pan with parchment paper.
In a large bowl, mix together dry ingredients rolled oats, flour, lemon zest, baking powder, and salt.
In the separate bowl, mash banana with the fork. Add honey or syrup and vanilla extract and mix well until you get a smooth mixture.
Add banana mixture to oat mixture. Add coconut oil and mix until everything is well combined and a dough is formed.
Transfer the mixture into prepared baking pan. Using fingers or a spatula pressed the mixture down tightly and evenly. Bake for 10 minutes.
Meanwhile, prepare the topping. Mix all ingredients. Use your hands to incorporate the coconut oil and mix just until dough forms. It should not be very crumbly but should stick together. Set aside.
Remove the pan from the oven. Spoon raspberry chia jam over the surface and spread it evenly. Add blueberries. Sprinkle topping mixture on top, pressing down lightly. Bake for 30 minutes until the top turns a light golden brown.
Remove from the oven and let it cool completely. Cut into bars and enjoy!
For raspberry chia jam:
Put fresh raspberries in a saucepan on a low heat. Mash raspberries with the fork. Simmer until the raspberries soften, for a few minutes.
Remove from heat and stir in syrup or honey or stevia and chia seeds. Stir for few minutes, and leave until mixture thickens for about 5 minutes.
Use the jam for making Berry Banana Breakfast Oat Bars. Store jam leftovers in a glass jar and refrigerate. The jam will keep in the fridge for up to 1 week.
Notes
* For gluten-free version make sure you use certified gluten-free products. Keep in an airtight container at room temperature for up to 1 week. As a measure, I used UScup (240ml).