One-Layer Chocolate Fudge Rum Cake

Heat oven to 325°F. Butter bottom and sides of 10 inch springform pan. Line bottom with circle of kitchen parchment or waxed paper; butter paper.

Combine flour, baking powder, salt, and baking soda in food processor; process 5 seconds. Transfer to small bowl; reserve. Combine chocolate, sugar, and cocoa powder in food processor; process 1 minute. With motor running, add boiling water. Add 3/4 cup butter; process 1 minute. Add eggs; process 1 minute. Scrape down sides of bowl, then add sour cream and rum; process 5 seconds. Add reserved flour mixture; process, using 4 to 5 on/off motions, only until batter is smooth. Do not over process, or batter will be too thin.

Pour mixture into prepared pan. Bake in middle of oven until wooden pick inserted in center is withdrawn clean and cake pulls away from sides of pan, 45 to 50 minutes.

Meanwhile, make chocolate rum glaze recipe.

Remove cake from oven; cool completely in pan on wire rack. Remove sides of pan; invert cake onto serving plate. Lift off bottom of pan; remove parchment paper. Pour cool chocolate glaze over cake; spread evenly over sides and bottom, using thin flexible metal spatula.