Ganache-filled Devil's Food Cake

• 9 cake pans
• 4 eggs
• 1/2 chocolate mixture
• 900 gr confectioners sugar
• 425 ml boiling water
• 375 gr packed dark brown sugar
• 290 gr semisweet chocolate
• 250 gr sifter cake flour
• 170 gr unsweetened cocoa powder
• 160 gr butter (unsalted)