Preheat the oven to 325 degrees F (165 degrees C). Grease a 9x5-inch loaf pan.
Whisk together flour and baking powder in a bowl. Cream together sugar and cream cheese with an electric mixer until fluffy. Stir in yogurt. Add eggs one at a time, beating well after each addition. Add vanilla bean paste. Slowly add flour mixture, beating on low speed and taking care not to overmix batter.
Warm chocolate-hazelnut spread in the microwave at 360 W until warm but not bubbling, about 1 minute. Stir and check consistency. Microwave for an additional 30 seconds if necessary.
Pour 1/2 of the cake batter into the prepared loaf pan. Pour in 2/3 of chocolate-hazelnut spread in a swirl over the batter. Pour in remaining batter and swirl remaining spread over the top. Use a bamboo skewer to create more swirls by running the skewer through the batter in a circular motion. Take care not to stir the mixture, but simply create a marbled design.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 50 minutes. Allow to cool before removing from the pan.
