Marbled Chocolate Bundt Cake

Preheat the oven to 350°F.

Place the butter in a 12-cup Bundt pan and grease the pan with your fingers, making sure to grease all the nooks and crannies. Sprinkle the flour all over the pan and knock out the excess.

Combine the sugar, cocoa powder, coffee, and honey in a small saucepan and cook over medium heat until the sugar has dissolved and the syrup starts to boil. Bring to a simmer, whisking to make sure there are no lumps. Remove from the heat and stir in the vanilla.

Place the sugar and butter in the bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed until the butter looks light in color and fluffy, about 2 minutes. Add the vanilla and mix until incorporated.

Add the eggs one at a time, beating until completely incorporated and scraping down the sides and bottom of the bowl between each addition. Add the baking powder, baking soda, and salt and beat until the dry ingredients are absorbed.

Add the flour in 3 additions and the buttermilk in 2, alternating between the flour and buttermilk and ending with the flour. Beat until incorporated and scrape down the sides and bottom of the bowl between each addition. Gently fold in the chocolate chips.

Stir one-third of the batter into a medium bowl and add the chocolate syrup. Incorporate completely and set aside.

Spoon half of the remaining vanilla batter into the prepared Bundt pan. Scrape the chocolate batter on top. Spread the remaining vanilla batter on top of the chocolate batter.

Insert a butter knife or chopstick into the batter and make "figure eight" motions throughout the entire cake to marble the batter. You may want to sometimes dig deep to the bottom and sometimes lift up to make sure the batter really moves around. Just don't overmix the batters, or else they will blend together instead of marbling.

Place the pan on a rimmed baking sheet. Bake until a toothpick or skewer inserted in the center comes out clean and the cake springs back when pressed down lightly, 50 to 60 minutes.

Let the cake cool in the pan on a wire rack for 20 to 30 minutes and then invert onto a serving plate while still warm. If the cake doesn't unmold, gently slip a very thin knife between the cake and the pan all the way around to loosen it and then try again.

Slice the vanilla bean lengthwise, if using, and scrape the seeds into the milk in a large bowl. Chop the bean in half and toss the pod in with the milk as well. Let steep in the refrigerator as the cake cools.

Once the cake has cooled completely (after about 2 hours), remove the vanilla bean from the milk and sift 2 cups powdered sugar into the milk. (If using the vanilla extract, add it to the milk right before sifting the powdered sugar; no need to steep it.) The glaze should be thin enough to pour, but thick enough to hold its shape on the cake, similar to honey in consistency. If the glaze is too thin, add more powdered sugar, 1 tablespoon at a time, until it reaches the desired thickness.

Drizzle the glaze on top of the cake, making sure it drips down the sides.

[Emma's Tip: Tuck parchment paper under the cake while you drizzle to catch the drips, then remove once the icing is set.]

If decorating with chocolate pearls, shavings, or sprinkles, sprinkle them randomly on the cake before the glaze dries.