Preheat the oven to 425 degrees F. Place the pie crust in a 9-inch pie dish and crimp the edges neatly. Keep it chilled while you make the filling.
In a large bowl, whisk together the pumpkin puree, brown sugar, eggs, evaporated milk, cinnamon, ginger, nutmeg, salt, and alcohol-free vanilla until smooth and well combined.
Pour the filling into the crust. Bake for 15 minutes, then reduce the oven temperature to 350 degrees F and continue baking for 35 to 45 minutes, until the center is just set.
While the pie cools slightly, combine the butter, brown sugar, and cream in a small saucepan over medium heat. Stir until melted and smooth, then add the chopped pecans and cook briefly until glossy.
Spoon the praline topping over the warm pie and spread it gently. Let the pie cool completely so the topping sets before slicing.