Before you start, have all ingredients at room temperature.
Preheat oven to 350 degrees F (177 degrees C). Brush an 8 x 8 inch pan with oil. Cut a piece of parchment paper the width of the bottom of the pan and long enough to overlap the two sides of the pan. Brush parchment paper with oil, set aside.
In a medium bowl, combine eggs, powdered stevia and alcohol free vanilla. Whisk until mixture is frothy and pale yellow in color, set aside.
In the bowl of a food processor, combine hazelnut butter, cubed avocado, unsweetened applesauce, melted coconut oil, baking soda and salt. Process until smooth. Add egg mixture and process until just combined.
Pour mixture into prepared pan, sprinkle with chopped hazelnuts and bake 20 minutes. Cool completely before serving.
HOW TO MAKE HOMEMADE HAZELNUT BUTTER
First remove hazelnut skins by spreading 3 cups of hazelnuts onto a rimmed baking sheet and roasting for 10-15 minutes, until skins begin to crack.
Then place hazelnuts on a clean kitchen towel, wrap them up and rub vigorously for 1 to 2 minutes, removing most of the skins.
Place hazelnuts into the bowl of a food processor and process, scraping the sides of the bowl from time to time, until butter reaches a smooth, shiny consistency, about 6 to 8 minutes.
Store hazelnut butter in a container with a tight-fitting lid in the fridge for up to 6 weeks.