Preheat oven to 350 degrees F.
Lightly grease an 8x8 pan and set aside.
Melt butter in the microwave or on the stove over low heat in a small saucepan.
In a medium sided bowl, add the melt butter and stir in brown sugar.
Add chia eggs and vanilla; beat until smooth.
Add dry ingredients and mix well.
Add 2 cups walnuts and stir.
Spoon into cake pan and bake for 25-30 minutes.
Make Icing: In a pot heat the butter and brown sugar until boiling. Remove from heat.
Add milk and stir, return to stove until boiling, about 20 seconds.
Remove from heat and let cool slightly for 2 minutes.
Add icing sugar and beat until smooth golden colour and it can hold it's shape.
Make Blondies: Let cake completely cool.
Once cake is completely cooled, spread icing on top.
Sprinkle with chopped walnuts and refrigerate until icing is set.
Cut into 16 squares. Store covered in the refrigerator.