Step 1

Preheat the oven to 350 degrees F (175 degrees C).

Step 2

Make the crust: In a large mixer bowl, combine the flour, brown sugar, and softened butter. Beat at medium speed until the mixture resembles fine crumbs, about 2 to 3 minutes. Transfer the mixture to an ungreased 13x9-inch baking pan. Pat the mixture evenly over the bottom of the pan to form a crust.

Step 3

Make the turtle layer: In a small saucepan over medium heat, combine ⅔ cup butter and ½ cup brown sugar. Cook and stir until bubbles form over the entire surface. Continue to cook, stirring constantly, for 30 to 60 seconds more. Remove from the heat.

Step 4

Assemble: Sprinkle the pecan halves evenly over the crust, then pour the hot brown sugar mixture on top.

Step 5

Bake: Place the pan in the preheated oven and bake until the entire surface is bubbly, about 18 to 20 minutes.

Step 6

Add the chocolate topping: Remove the bars from the oven and set them on a wire rack. Immediately sprinkle the milk chocolate chips evenly over the surface. Let them stand until the chocolate melts, about 2 to 3 minutes. Use a knife or small spatula to swirl the melted chocolate slightly.

Step 7

Cool: Allow the bars to sit until completely cooled, about 30 minutes. Once cooled, use a sharp knife to cut the bars into 48 pieces.