Preheat your oven to 350°F (175°C). Line a 9x13 inch baking pan with parchment paper, leaving an overhang on the sides to easily lift the bars out later. Lightly grease the parchment paper.

In a large mixing bowl, cream together the softened unsalted butter, granulated sugar, and light brown sugar with an electric mixer until light and fluffy (about 2-3 minutes).

Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In a separate medium bowl, whisk together the all-purpose flour, baking soda, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix.

Fold in 1 cup of the Heath English Toffee Bits with a rubber spatula until evenly distributed throughout the dough.

Press the cookie dough evenly into the prepared 9x13 inch baking pan. Sprinkle the remaining 1/2 cup of toffee bits over the top of the dough.

Bake for 22-25 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out with moist crumbs, not wet batter. Do not overbake to keep them chewy.

Remove the pan from the oven and let the bars cool in the pan on a wire rack for at least 15-20 minutes before adding the drizzle.

While the bars are cooling, prepare the chocolate drizzle. In a small microwave-safe bowl, combine the semi-sweet chocolate chips and heavy cream. Microwave in 30-second intervals, stirring after each, until the chocolate is melted and smooth. This typically takes 60-90 seconds.

Once the bars have cooled slightly, drizzle the melted chocolate mixture over the top using a spoon or by transferring it to a small piping bag (or a Ziploc bag with a corner snipped off).

Allow the chocolate to set completely at room temperature (or refrigerate for 15-20 minutes to speed up the process). Once set, use the parchment paper overhang to lift the entire slab of Toffee Cookie Bars from the pan. Transfer to a cutting board and cut into 24 squares or desired bar size.