Step 1

Preheat oven to 350ºF. Spray bottom and sides of a 9-inch springform pan with nonstick cooking spray, then line bottom of pan with parchment paper, and spray parchment paper with nonstick cooking spray.

Step 2

Bring 2 inches of water to a boil in a saucepan. Carefully place a heat-proof bowl over boiling water (so that it’s not touching water) and add chocolate and butter to bowl. Stir constantly until chocolate is melted and combined with butter (see note).

Step 3

Remove from heat, stir in oil, and add vanilla, cinnamon, chile powder, and salt, stirring until completely blended together. Set aside to cool.

Step 4

Meanwhile, In a separate large bowl, beat eggs and sugar with an electric mixer on medium-high speed until mixture is light in color and fluffy in texture, about 4 minutes.

Step 5

Fold in the chocolate mixture until just combined. Pour batter into prepared springform pan. Bake until the cake is just set and the top is beginning to crack, about 35 minutes.

Step 6

Let cool completely in the pan on a wire cooling rack, about 1 hour. Remove the pan sides and cover the cake and refrigerate for at least 3 hours or up to 3 days.

Step 7

Flavor and texture of cake is best if you let it stand at room temperature for 30 minutes prior to serving. Use a very sharp knife to cut slices, cleaning the knife between cuts.

Step 8

Serve topped with confectioners’ sugar, whipped cream, ganache, or fresh fruit.