Preheat the oven or toaster oven to 350ºF and line a cookie sheet with parchment paper.
Spread the chopped slivered almonds evenly over the cookie sheet. Toast in the oven or toaster oven for 5-8 minutes, keeping a close eye to ensure they don't burn. Set aside to cool and turn off the oven.
In a medium bowl, use a hand mixer on medium speed to beat the aquafaba until consistently foamy (about 2 minutes).
Add the sugar, oil, and almond extract to the bowl containing the aquafaba and blend on medium until smooth.
Add the flour, baking powder, and cinnamon to the bowl and blend until well combined.
Fold in 1 cup of the toasted slivered almonds with a rubber or silicone spatula until well distributed. Place the remaining toasted almonds in a small bowl and set aside.
Cover the bowl with plastic wrap or place batter in an airtight container and put it in the fridge for at least two hours, or overnight.
Preheat the oven to 350ºF. Divide the batter into four flat logs and arrange them on two parchment paper-lined cookie sheets. Bake for about 30 minutes, until the edges are golden brown.
Allow the logs to cool for about 25-30 minutes. (You will reuse the parchment-lined cookie sheets in the next step.) Lower the oven temperature to 250ºF.
Transfer the cooled logs to a cutting board and use a sharp knife to slice each log into 8-10 pieces. Place the cookies on their side on the parchment-lined cookie sheets. Bake for 15-20 minutes until crisp. Turn off the oven and leave the cookies in the oven to rest for another 30 minutes or so.
Place the chocolate chips or wafers in a microwave-safe bowl and microwave in 15-second intervals, stirring in between. Once the chocolate is melted, dip each cookie in the chocolate so that about ⅓ of the cookie is covered; you can also use a spoon to add the melted chocolate. Sprinkle with some of the remaining toasted almonds, and place the cookies back on the baking sheet. Allow the chocolate to set at room temperature or place the cookie sheets in the refrigerator for setting.