Line a rimmed half-sheet pan completely with foil and spray with the cooking spray.
Arrange the crackers in a single layer over the entire sheet pan, breaking crackers in half as necessary to fit.
In a medium saucepan, melt the butter over medium heat. Add the brown sugar and bring to a boil until it forms an amber caramel and the temperature reaches 300°F on a candy thermometer, 4 to 5 minutes. Remove from the heat and stir in the vanilla. Immediately pour the mixture over the crackers, spreading it into an even layer.
Meanwhile, in a microwave-safe bowl, heat the chocolate chips in the microwave at 50% power until melted and smooth, 1 to 2 minutes, stirring every 15 seconds. Stir in the chocolate-hazelnut spread. Microwave for 15 seconds more to make a smooth mixture. Pour the chocolate mixture over the toffee crackers, spreading into an even layer.
Top with the sprinkles, candy, and toasted almonds. Refrigerate the crackers until set, about 2 hours.
Carefully remove the foil and break the cracker candy into pieces.
