Preheat oven to 375°F (190°C) and adjust oven rack to the middle position.

Spray a 12-cup muffin tin with baking spray to prevent sticking.

In a medium bowl, melt the bittersweet chocolate chips, unsalted butter, and mole together.

Microwave for 1 to 2 minutes, stopping every 20 seconds to stir until fully melted and smooth.

Stir in the packed brown sugar, espresso powder, ground cinnamon, vanilla extract, and salt until well combined.

Transfer the chocolate mixture to a stand mixer bowl (or a large bowl if using a hand mixer).

Add the all-purpose flour and beat on medium-low speed until just incorporated, about 30 seconds.

Increase the mixer speed to medium and add the eggs, one at a time, beating thoroughly after each addition.

Increase the speed to high and beat until the mixture is creamy and lightens in color, about 1 minute.

Cover the bowl with plastic wrap and refrigerate the mixture for at least 30 minutes or up to 24 hours to allow flavors to meld.

Divide the batter evenly among the prepared muffin cups, filling each about two-thirds full.

Bake in the preheated oven for 10 to 12 minutes, or until the cakes are cake-y outside but still indented and gooey in the middle.

Transfer the muffin tin to a cooling rack and let the cakes cool slightly.

Carefully remove the cakes from the tins using a small spoon and transfer them to individual plates.

Serve the warm cakes with optional Kahlua-spiked whipped cream and toasted sesame seeds.

(Optional) To make the Kahlua-spiked whipped cream, whip the heavy cream, Kahlua, and a pinch of salt in a chilled bowl until soft peaks form, about two to three minutes.