Preheat oven to 325°F (160°C).

Grease a 9-inch square baking pan.

In a medium bowl, combine powdered sugar, softened butter, and whipping cream.

Blend the ingredients well until smooth.

Lightly spoon the flour into a measuring cup and level it off.

Add the flour to the sugar mixture and mix until a crumbly dough forms.

With floured hands, press the dough evenly into the prepared baking pan.

Bake for 15-20 minutes, or until the crust is firm to the touch.

While the crust bakes, combine unwrapped caramels and whipping cream in a medium saucepan.

Cook over low heat, stirring occasionally, until the caramels are melted and the mixture is smooth.

Remove from heat and add pecan halves, stirring well to coat them in the caramel mixture.

Immediately spoon the caramel pecan mixture over the baked crust, spreading it carefully to cover the entire surface.

In a small saucepan over low heat, melt butter and chocolate chips, stirring constantly.

Stir in whipping cream and drizzle the melted chocolate over the caramel pecan filling.

Refrigerate for 1 hour, or until the filling is firm.

Cut the chilled bars into squares and serve.