In a small saucepan, combine 25 caramels and 1/4 cup evaporated milk. Heat over medium-low, stirring constantly, until the caramels are fully melted and the mixture is smooth.
Remove the saucepan from heat and stir in 1/2 cup chopped pecans. Pour the caramel-pecan mixture evenly into the Oreo pie crust and smooth the top with a spatula.
Refrigerate the crust with the caramel layer for at least 20 minutes to set.
In a large bowl, beat 6 ounces softened cream cheese and 1/2 cup sour cream together until smooth and free of lumps.
In a separate bowl, whisk the 1 (3.9-ounce) package instant chocolate pudding mix with 1 1/4 cups cold milk for about 2 minutes, until the pudding begins to thicken.
Add the prepared pudding to the cream cheese mixture and beat until completely combined and smooth.
Spread the chocolate-cream cheese mixture evenly over the chilled caramel layer.
Refrigerate the assembled pie for at least 1 hour to set.
To serve, warm the Hot Fude Ice Cream topping until pourable (for example, microwave in short bursts, stirring between bursts, or warm gently in a small saucepan). Drizzle the warmed topping over the pie and sprinkle with 1/4 cup toasted chopped pecans.