Preheat the oven to 180°C (356°F).
In a large bowl, mix together flour, sugar, cocoa powder, baking powder, and salt.
In a separate bowl, whisk together the eggs and melted butter, then add Nesquik and milk, mixing well to combine.
Pour the wet ingredients into the dry ingredients and fold together using a spatula.
Chop the Twix bars into small pieces and mix them into the batter.
Pour the batter into a baking pan and spread evenly.
Bake at 180°C (356°F) for 20-25 minutes.
Let it cool and cut into pieces for serving.