Preheat oven to 375ºF. Place hazelnuts on a sheet pan and roast for 10-12 minutes until fragrant and just starting to brown. Remove from the oven to a clean tea towel. Wrap towel around the hazelnuts and rub together for 2 minutes to release some of the skins.
Make sure you've put 1/2 a cup of water in the freezer to get really cold.
Place the hazelnuts in a food processor with the S-blade attached. Turn on high for 2-3 minutes until a runny hazelnut butter forms, scraping down the sides a couple times. It should be a similar consistency to runny natural nut butter.
Add the chickpeas, cocoa powder, maple syrup, sugar, vanilla extract and salt. Buzz in the processor on high for 1 minute until smooth, but thick. Scrap down the sides. Turn back on low and slowly drizzle the ice water in. Turn up to high and let run for 2 minutes until totally smooth.
Put the hummus in an airtight container and refrigerate for at least 20 minutes to cool down and let the flavors come together. Serve with fruit, graham crackers, pretzels or just a spoon ;)