Preheat the oven to 180 C. In a large bowl, cream together the butter and brown sugar until light and fluffy. Beat in the egg yolks then stir in the vanilla. Stir in the flour and mix well.
Beat egg whites until foamy and spread in a shallow dish. Spread walnuts on a plate or on greaseproof paper.
Roll 1 tablespoon of the biscuit dough into a ball; roll in egg whites, then in walnuts. Place 5cm apart on a baking tray. Make a depression in each ball with your thumb.
Bake in the preheated oven for 12 to 15 minutes.
When the biscuits have cooled, melt the chocolate in the microwave. Spoon just a bit of the melted chocolate in the hollows of the biscuits, then place 2 to 3 mini eggs (depending on their size) into the hollows. Allow to cool long enough so that the chocolate hardens and the eggs are secure in the nests.
Will make these before Easter, what a novel idea. I purchased a packet of speckled tiny candy coated eggs last week. Just was waiting for inspiration to use them. Now this recipe arrived at the right time. Love the idea of the walnuts as well. That's the healthy bit. Thanks. I am now Inspired. - 14 Apr 2014