Nutella Loaf Cake Recipe

Preheat oven to 350 degrees F (180 degrees C). Lightly butter and line with parchment an 8- by 5-inch loaf pan. Set aside. 

In a large bowl, mix flour, baking powder, baking soda, salt, and cocoa powder. Set aside.

In the bowl of a stand mixer, beat butter, sugar, and Nutella together until light and fluffy. Add and beat in eggs, one at a time. Gradually add flour mixture alternating with the milk. Mix only until blended. 

Transfer to the prepared loaf pan. Bake in the preheated oven for 40 minutes or until a skewer inserted in the cake emerges clean. Cool on a wire rack.

Meanwhile, make the buttercream: In a double boiler, add sugar, egg whites, and salt. (Add 1/8 teaspoon cream of tartar if desired.) Using a silicone spatula, stir ingredients over the simmering water until the sugar and salt granules have dissolved and egg whites are warmed (To pasteurize egg whites, heat to about 160°F (or 70°C) on a candy thermometer).

Remove egg whites from heat and place in the stand mixer. (You can also use an electric mixer.) With the whisk attachment, whisk egg white mixture on High until it has cooled enough to the touch. Once egg whites are cool, add butter, a cube at a time, until fully combined, scraping the bowl as needed and mixture has become light and fluffy. Turn off the mixer, and add Nutella. Mix on Medium speed until just incorporated, scraping down the sides of the bowl as needed.

When ready to serve, lift cooled cake from the loaf pan and discard the parchment paper. Top with buttercream. Slice and serve.