Melt half the butter in a pan and add it to the remaining butter in a bowl.
Combine the flour, cocoa powder and salt.
Combine the eggs, sugar and vanilla paste together in mixer fitted with the whisk attachment. Once combined add the dry ingredients and butter alternately with the mixer going.
Once combined fold in the chocolate chips. Place the mixture in a piping bag and leave in a cool place for 2 hours. This can be refrigerated but must be brought back to room temperature prior to piping in to the moulds.
Spray the moulds with non-stick spray.
Pipe in to the moulds.
Bake at 180C for 12-15 mins until skewer comes out clean. Leave in moulds for 10 mins (this will help maintain their shape), turn out and cool completely.
Dust with icing sugar once completely cooled.
n.b. - We use a mini muffin mould from Lakeland to get that perfect size of chocolate bouchon. Feel free to pop in the deli and we'll show you which one.