Chocolate Snickerdoodle Cake

Place a rack in the center of the oven and preheat the oven to 350 degrees F. Generously grease two 9" round cake pans with solid vegetable shortening, then dust with flour. Shake out the excess flour. Set pans aside.

Place the cake mix, milk, oil, eggs, cinnamon and vanilla in a large mixing bowl. Blend with an electric mixer on low speed for 1 minute. Stop the machine and scrape down the sides of the bowl with a rubber spatula.

Increase the mixer speed to medium and beat 2 minutes more, scraping down the sides again if needed. The batter should look well combined. Divide the batter evenly between the prepared pans, smoothing it out with the rubber spatula. Place the pans in the oven side by side.

Bake the cakes until they spring back when lightly pressed with your finger, 28-32 minutes. Remove the pans from the oven and place them on wire racks to cool for 10 minutes. Run a dinner knife around the edge of each layer and invert each onto a rack, then invert again onto another rack so that the cakes are right side up. Allow to cool completely, 30 minutes more.

Meanwhile, mix the Cinnamon-Chocolate Cream Cheese Frosting ingredients.

Place one cake layer, right side up, on a serving platter. Spread the top with frosting. Place the second layer, right side up, on top of the first layer and frost the top and sides of the cake with clean, smooth strokes.

Place this cake, uncovered or in a cake saver, in the refrigerator until the frosting sets, 20 minutes. Then store it in a cake saver or under a glass dome at room temperature for up to 3 days, or in the refrigerator for up to 1 week. Or freeze it, wrapped in aluminum foil or in a cake saver, for up to 6 months. Thaw the cake overnight in the refrigerator before serving.