In a large bowl, combine Greek yogurt, pumpkin, toffee bits, pumpkin pie spice and salt. Whisk until ingredients are all well blended.
Scoop about two heaping tablespoons of filling into individual pie crusts. If you have some leftover, evenly distribute across crusts. Cover with plastic wrap and refrigerate until ready to serve.
To serve, top with whipped cream. Garnish with candy pumpkins and sprinkles (if using). Refrigerate until ready to serve.