In the top of a double boiler, whisk together egg yolks and sugar. Cook over simmering water for 8 minutes, stirring constantly. Remove from heat, and transfer to a large bowl. With a mixer at medium speed, beat yolk mixture until thick and lemon-colored. Add mascarpone, and beat until combined.
In a medium bowl, using clean beaters, beat cream, coffee liqueur, and zest with a mixer at medium speed until stiff peaks form. Gently fold whipped cream into yolk mixture until combined.
In a small bowl, combine coffee and orange juice. Dip ladyfingers in coffee mixture.
In 4 (8-ounce) serving bowls or ramekins, layer 1½ ladyfingers in bottom of each dish (some pieces may have to be broken to fit). Top each with ¼ cup cream mixture. Repeat layers with remaining 6 ladyfingers and 1 cup cream mixture. Refrigerate for at least 4 hours or overnight.
In a small bowl, combine cocoa and cinnamon. Dust top of tiramisu with cocoa mixture before serving. Garnish with chocolate curls and zest, if desired.
Notes
*We used Alessi Biscotti Savoiardi.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/blood-orange-tiramisu-recipe/