Place the chopped white chocolate in a glass bowl and set aside.
Add the egg yolks and sugar to a small bowl and whisk until pale yellow.
In a saucepan, over low heat, bring ¼ cup of cream to a simmer. Remove from heat and slowly add the cream into the yolk and sugar mixture. Pour the mixture back into pan and stir with a wooden spoon until it coats the back of the spoon.
Pour hot mix into a bowl with the chopped chocolate. Stir until completely smooth.
In another bowl, whip remaining 1 cup of the cream to almost stiff peaks. Fold half the whipped cream into the white chocolate and mix. Next, fold in the remaining whipped cream to the mousse.
Spoon the white chocolate mousse into 4 small serving cups and refrigerate until set, approximately 1 hour. Garnish with chocolate chips for the "ghost eyes".