Grease an 8-inch baking pan with cooking spray and line with parchment paper, allowing overhang on all sides, then grease the paper.
Put the chocolate in a heatproof mixing bowl and set over a pot of gently simmering water. Heat, stirring constantly, until the chocolate is completely melted. Off heat, stir in the coconut oil, cinnamon and salt. Pour half of the chocolate into the bottom of the pan, spread evenly with a small offset spatula and place in the freezer for 10 minutes to set. Reserve the remaining chocolate.
In a medium-size heavy saucepan, combine the shredded coconut, condensed milk and 1/4 cup water over low heat. Cook, stirring constantly, until the coconut softens, about 10 minutes. Let cool.
Remove the pan from the freezer and spread the coconut mixture evenly over the chocolate with an offset spatula until smooth. Chill in the freezer for 30 minutes.
Pour the second half of the melted chocolate over the coconut mixture and spread in an even layer. Chill in the freezer until set, about 1 hour.
Remove the turrone from the pan, peel off the parchment, cut into rectangles and wrap in wax paper. Return to the freezer until ready to eat.