Preheat the oven to 400°F. Line a rimmed baking sheet with parchment and set aside.
Drain and rinse the chickpeas really well under cold water. Transfer them to a paper towel or clean kitchen cloth lined plate. Pat the chickpeas completely dry! You may need to change out the paper towels or cloth if they get too wet and dry the chickpeas again.
Remove any loose chickpea skins as they may burn in the oven. It is not necessary to remove the skins that are still firmly attached to the chickpeas.
Transfer the chickpeas to a clean bowl and drizzle with the oil. Pour them out onto the prepared baking sheet and roast for 40 to 45 minutes until crunchy, stirring every 10 to 15 minutes to prevent burning. Check them more often towards the end of the roasting time as they can go from crisp to burnt quickly.
Once they are sufficiently crunchy, transfer them back to the bowl and drizzle with maple syrup and vanilla. Toss to coat evenly. Then add the cinnamon, sugar, and salt and mix well.
Pour them back out onto the baking sheet in one even layer to continue to cool completely. To get extra crunchy chickpeas, turn the oven off and put them back in the oven with the door ajar and let them continue to cool in there.
These are best eaten on the day you make them.