1 cup Nutella, divided
4 large eggs, divided
1 (18.25 ounce) box yellow cake mix
1/2 cup buttermilk
1 cup confectioners' sugar
2 tablespoons Frangelico liqueur or hazelnut syrup

Preheat oven to 350 degrees F. Lightly grease and flour 10-inch Bundt pan.

In small bowl, whisk together 2/3 cup Nutella and 1 egg. Blend until completely smooth and set aside. In large bowl, using electric mixer on low speed, stir together cake mix, remaining 3 eggs, buttermilk and remaining 1/3 cup Nutella until moistened. Scrape down sides and beater(s) and increase speed to medium, beating for another 2 minutes.

Remove 1 cup batter and mix with RESERVED Nutella-egg mixture. Pour leftover batter evenly into prepared cake pan. Spoon RESERVED Nutella batter over it and, using a knife, gently swirl batters together to create marble pattern. Smooth top of cake and bake for 40 to 50 minutes. (Cake is done when moist crumbs cling to inserted wooden pick.)

Allow cake to cool in pan for 15 minutes. When ready to handle, carefully invert onto cooling rack and remove pan. While cake continues to cool, make glaze by whisking together confectioners sugar and Frangelico liquor until smooth. Drizzle glaze over cake.

Serving ideas: For a spring touch, sprinkle top of cake with candied orange and lemon slices.

Alternative: To make mini Bundt cakes, use 2 mini Bundt pans (6 cakes each) instead of a 10-inch Bundt pan and follow above instructions, dividing batters into 12 smaller cake forms. Bake cakes for 20 to 25 minutes.