Preheat oven to 350 degrees Fahrenheit.
Line an 8x8 baking pan with parchment paper.
Make a chia egg by combining chia seeds, water and corn starch. Let thicken for 10 minutes.
To a medium bowl, add coconut oil, mashed banana, sugar, vanilla extract and chia egg. Whisk together until evenly combined.
Add flour and salt. Mix evenly to form a thick, dough-y batter.
Fold in chocolate chips.
Pat blondie batter into baking pan and bake at 350 degrees for 20-25 minutes.
In the meantime, prepare peanut butter frosting by whisking together peanut butter, coconut oil, powdered sugar and plant milk.
Once the blondies are ready, allow them to cool for at least an hour.
Spread peanut butter frosting on top and garnish with additional chocolate chips.