For the Sourdough Sponge: In a mixing bowl, combine all ingredients with 500 grams water. Let sit 2 hours at room temperature.

For the Whole Wheat Bagels: In the bowl of a stand mixer fitted with a dough hook attachment, add flour, salt, sugar, yeast, and Whole Wheat Sourdough Sponge. Mix 5 minutes on low speed. Transfer dough to a lightly floured work surface. Portion into 10 pieces, then form into rounds. Using your thumb, form a hole in the center of each piece and stretch until each piece is 5 inches wide. Transfer rounds to a parchment-lined sheet tray. Cover with plastic wrap and refrigerate overnight.

The next day, heat oven to 500°F. Bring a large pot of water to a boil. Add baking soda. Working in batches, add dough rounds, flipping over after 5 seconds. Remove from water and transfer to a parchment-lined sheet tray. Bake 15 minutes, rotating tray halfway through. Let cool.

For the Honey-Vanilla Cream Cheese: In a stand mixer fitted with a whisk attachment, whip cream cheese. Add honey and vanilla bean paste and whip until just combined. Transfer to an airtight container and refrigerate.

To Assemble and Serve: Slice and toast 1 Whole Wheat Bagel. Smear 2 ounces Honey-Vanilla Cream Cheese and 1 ounce Nutella on each Whole Wheat Bagel half. Top each half with seasonal fruit, toasted hazelnuts, and fresh mint. Serve open-faced.