Preheat oven to 350F (180C) and grease a mini muffin tin (total 36 mini- muffin cups).
Over a pot of barely simmering water melt butter for 1 minute, then add chocolate and stir gently until melted. Remove chocolate from heat to cool for 5 minutes.
Whip eggs with sugars using electric beaters until thick and frothy. By hand, stir in melted chocolate. Stir flour, baking powder and salt , then gently stir into chocolate mixture. Stir in Skor bits and spoon into prepared mini muffin tins. Bake for 18 to 20 minutes, until a rich golden colour. Cool to room temperature before removing.