In a saucepan over medium heat bring the butter brown sugar and corn syrup to a boil. Remove from heat
Add the flour and nuts into the butter mixture. Stir until cooled, about 10 minutes.
On a parchment paper-lined baking sheet, use a teaspoon to scoop 5 balls 5 inches (13 cm) apart onto the baking sheet.
Bake for 6-7 minutes, until the edges are a deep golden color.
Let the cookies cool for about 1 minute, until they are cool enough to handle but still flexible.
Place the cookie over the backside of a muffin tin and gently form until the cookie is a cup shape. Wait until the cookie has hardened into the cup shape then remove from the muffin tin, about 1 minute.
In a bowl, microwave the chocolate in 20-second intervals stirring in between for 1 minute.
Take one of the pecan lace cookie cups and dip the edge into the chocolate. Let cool.
Place one scoop of ice cream in the cookie cup, pour hot fudge over the ice cream, top with nuts. Serve immediately.