In a mixing bowl combine the granulated sugar, 1 teaspoon cinnamon, lemon juice, salt, and bourbon. Add the pears and toss to combine. Then add the cornstarch toss again and pour into the baking dish.
In a food processor pulse the flour, brown sugar, cardamon, butter, remaining cinnamon, walnuts, and oats. Pulse until the mixture resembles coarse meal and sprinkle evenly over the top of the pears.
Bake for 30 minutes or until the top has reached a nice golden brown. If you want the pears more tender cook for an additional 15 minutes.