Sift the flour, cocoa, ancho chile powder, baking soda, baking powder, and salt onto a sheet of waxed paper. Sift again.
Place butter and sugar in the bowl of an electric mixer fitted with the paddle attachment and beat at high speed until smooth and fluffy. Add the eggs, 1 at a time, beating until each is incorporated. Continue beating, scraping down the sides of the bowl if necessary, until light and fluffy, about 5 more minutes. With the mixer on low speed, beat in 1/3 of the flour mixture. Beat in the vanilla, half of the buttermilk and half of the coffee, then another 1/3 of the flour mixture. Beat in the remaining buttermilk and coffee, then the remaining flour mixture.
Spread the batter evenly in prepared pans. Bake for 30 minutes, or until the centers spring back when lightly pressed. Cool the cakes in the pan on a wire rack.
Whipped Ganache Filling:
Bring heavy cream to a simmer in a small saucepan. Place chocolate in a large bowl, pour heavy cream over and let sit for 1 minute. Gently whisk until combined.
Place the ganache over a bowl filled with ice water to chill slightly, whisking occasionally. Remove ganache from the ice and whip with a whisk until light and fluffy. Fold in the toffee bits.
In the bowl of a stand mixer fitted with a wire whip attachment, beat the egg yolks at medium-high speed until creamy and pale yellow, about 5 minutes.
In a nonstick saucepan, combine the sugar and corn syrup. Place over medium-high heat and bring to a full rolling boil without stirring and cook until it reaches soft-ball stage (238 to 242 degrees F) on a candy thermometer. Immediately pour the mixture into a buttered heat proof measuring cup to halt the cooking.
Add a small amount of the syrup to the beaten egg yolks, turn on the mixer to high speed, and beat for about 5 seconds. Continue stopping the mixer, adding syrup, and beating in the same manner until all of the syrup is incorporated and the mixture is cooled completely.
Add the butter, 1 piece at a time, and beat until incorporated before adding the next piece. When all of the butter has been blended in, add the vanilla and coconut milk and continue beating until combined.
Slice each cake in half horizontally to make 4 layers total. Place the first layer down and spread with a thin layer of the Ganache. Repeat with the remaining cake layers and ganache, ending with a cake layer.
Spread a thin layer of the buttercream over the entire cake. This is called a crumb coat. Chill the cake for about 30 minutes. Frost entire cake with the remaining buttercream. Press coconut into the sides of the cake.