Melt the butter in a pan and let it brown a little. Set it aside to cool.

Warm the milk in the same pot, then take it off the heat.

In a mixing bowl, combine the flour, cocoa powder, and sugar. Then, whisk in the eggs one by one.

Slowly blend in the butter and warm milk, then refrigerate the batter for about 30 minutes to chill.

Heat a nonstick skillet over medium heat. Pour about ¼ cup of the batter into the pan and swirl it to cover the bottom. Cook until golden brown on the underside, then flip it over.

Let the crepe cool on a rack. Repeat with the remaining batter until you have a stack of crepes.

Stack the crepes with layers of whipped cream in between each. Trim the edges to make it neat if desired.

For the ganache, bring the heavy cream and sugar to a boil, then pour it over the chocolate and butter in a bowl. Let it cool until it thickens.

Spread the ganache over the assembled crepe cake. Optionally, dust with powdered sugar before serving.