Heat oven to 350 degrees Fahrenheit. Line an 8-inch by 8-inch metal baking pan with parchment paper.
Place butter in a small sauce pan. Once melted, the butter will begin to foam and sizzle around the edges. Keep stirring. In about 5 minutes and the butter will turn golden brown. The butter will foam and milk solids may settle at the bottom of your pan but use a wooden spoon to scrape this. You will see dark brown milk solids which adds all the delicious flavour. Just make sure not to burn the butter (though I like mine pretty dark).
Remove the pan from heat and pour the butter into heat-proof bowl to stop the cooking process. Let cool slightly for about 5 -10 minutes.
In a medium bowl, stir the brown butter and brown sugar until blended. Add the egg, vanilla. The recipe calls for almond extract and I think this adds such a delicious bit of complexity to the blondies. Add your miso and mix. The batter is pretty thick but go with it.
When the batter looks well blended, add the flour and stir until fully incorporated. (again, the batter will be quite thick).
Fold in the 1/2 cup mini eggs. You may crush them into smaller pieces if desired.
After you spread batter in your lined baking pan, top with remaining 1/4 cup of mini eggs.
Bake for 20-21 minutes at 350 degrees
Let cool for 20 minutes before slicing into 9 squares of 12 rectangular pieces.