Preparation

1. In a small bowl dissolve the espresso powder in the half-and-half; reserve. Preheat oven to 350°F. Lightly coat a 9x3-inch springform or cheesecake pan with cooking spray.
2. Place the butter and 1⁄4 cup of the sugar in a medium bowl. Mix on Speed 2 to cream, 11⁄2 minutes. Add flour, cocoa, cinnamon, baking powder, and salt; mix on Speed 1 until combined, 30 seconds. Add egg yolk and mix on Speed 1 until crumbly, 15 seconds. Press into bottom of prepared pan. Bake in preheated oven for 10 minutes, until slightly puffed (crust may have cracked appearance – that is normal). Place on a rack to cool.
3. When the pan is cool to touch, wrap a sheet of aluminum foil around the bottom and sides of the pan so that it comes up at least 2 inches. Place cream cheeses and sugar in a large mixing bowl. Beat on Speed 1 until combined and smooth, 2 minutes. Using Speed 1, add eggs, one at a time, mixing for 15 seconds after each addition. Scrape the bowl. Add cornstarch; mix on Speed 1 for 20 seconds. Scrape the bowl. Add half-and-half mixture and vanilla, mix on Speed 1 until smooth and completely combined. Pour the mixture over the cooled crust. Place the pan in a larger aluminum pan and place in the oven; add enough hot water to the outer pan so that it is 1⁄2-inch deep. Bake in the preheated 350°F oven for 60 to 70 minutes, until the cheesecake is pulling away from the sides of the pan; the center will be jiggly.
4. Remove from the oven, remove the foil and let cool completely on a rack. Refrigerate at least 4 hours before serving. Garnish with chocolate curls if desired.

*Warm cold eggs safely before using by placing in a bowl of hot (not boiling) water for 10 minutes. They will incorporate more easily into your mixture.

Variation: After the cheesecake is mixed, add 3 ounces each chopped white and bittersweet chocolate using Speed 1, mix for 15 seconds to combine.