Step-by-Step Instructions:

• Step 1: Preheat your oven to 350°F (175°C). Grease your 9x9-inch baking pan or line it with parchment paper for easy removal.
• Step 2: In a mixing bowl, combine the graham cracker crumbs, ¼ cup of sugar, and the melted butter. Mix until the crumbs are completely coated and resemble wet sand. Press this mixture firmly into the bottom of the prepared baking pan to form an even layer.
• Step 3: Bake the crust in the preheated oven for about 10 minutes, or until it is lightly golden. Remove from the oven and set aside to cool slightly.
• Step 4: In a small saucepan over medium heat, combine the sweetened condensed milk, remaining ½ cup of sugar, instant espresso powder, and vanilla extract. Stir constantly until the mixture is smooth and begins to bubble. Allow it to simmer for 4-5 minutes until it thickens slightly.
• Step 5: Pour the caramel mixture over the baked graham cracker crust, spreading it evenly.
• Step 6: Sprinkle the chocolate chips over the warm caramel layer, allowing them to melt slightly. Use a spatula to spread the melted chocolate evenly over the top.
• Step 7: Refrigerate the bars for at least 2 hours or until set. Once firm, lift the bars out of the pan using the parchment paper. Use a sharp knife to cut them into squares.