In a mixing bowl, combine the crumbs, pecans, and butter together. Press into a 10-inch springform pan. Allow the crust to come up the sides of the pan.
For the filling: In a food processor, combine the cheese, sugar, and sour cream and blend until smooth. Add the eggs one at a time until incorporated. Dissolve the cornstarch in the cream and add to the cream cheese mixture. Fold in the pralines and vanilla. Pour the filling into the spring form and bake for 1 hour or until the cake has set. After cake removing from the oven, run a knife around the edges of the pan to prevent the cake from cracking.
Combine the topping ingredients and mix until smooth.
After the cake has cooled spread the topping evenly over the top of the cake and sprinkle the top of the cake with the graham cracker crumbs. Place a piece of the cake in the center of the plate.
Drizzle the praline sauce over the cake and sprinkle the pecans around the plate. Garnish with the whipped cream and fresh mint.
Mix the sugar, salt, evaporated milk, and butter in a heavy-bottomed saucepan. Cook over low heat, stirring constantly with a wooden spoon, until sugar dissolves. Stir in pecans and cook over medium heat until mixture reaches the soft ball stage. (234 to 240 degrees F on a candy thermometer; if you spoon a drop of boiling syrup into a cup of ice water, it will form a soft ball that flattens easily between your fingers.)
Remove pan from heat and stir rapidly until mixture thickens. Drop pralines by teaspoonfuls, 1-inch apart onto parchment paper-lined baking sheets; let cool completely until firmed up. Store in an airtight container.