Cocoa layered cake without eggs

Ingredients

• # For the base
• flour
• yogurt
• bicarbonate of soda
• sugar
• cocoa
• vanilla and grated chocolate in large pieces
• # For the buttercream
• butter
• powdered sugar
• chopped walnuts
• # For Creamy Cream
• pastry cream
• rodopcheta 3 or more blocks of chocolate
• cocoa optional