Gerbeaud Cakes (Metric)

Filling

• 225 g whole walnuts, shelled
  o bien 225 g hazelnuts, blanched
• 225 g sugar
• 1 lemon, zest only, no white pith
• 60 g raisins, dark

Dough

• 60 g whole milk
• 1 tsp dried yeast, active
• 225 g butter, unsalted, diced, room temperature
• 70 g sour cream
• 45 g sugar
• 1 egg yolk, from large egg
• 500 g all purpose white flour
• 1 tsp baking powder
• ¼ tsp salt
• 170 g apricot jam, divided
• 140 g dark chocolate chips
• 60 g butter, unsalted, diced