Preheat oven to 325°F.

One hour before, make the ganache for the filling so it has time to set. In a double boiler, over simmering water, melt the butter with the chocolate and cream. Let cool.

In a stand mixer with the paddle attachment, cream the butter and sugar until nice & fluffy. Add the eggs and continue to beat until well incorporated. Sift in the flour into the butter mixture beat slowly until all the ingredients are well combined.

Use a truffle scoop or soup spoon, form balls, and place onto a baking sheet not too close to each other. Bake for about 12-18 minutes until golden brown on the edges and light brown in the center. Carefully transfer to a cooling rack until set.

After cookies are fully cooled (very important!) turn the cookies upside down and spread with a little of the not so set ganache. Sandwich the cookies together in pairs and dust with a little cocoa powder.