1-First Step: Mise en place and cream wet ingredients. Soften 1 cup butter to room temperature. In a large bowl, beat butter with 1 cup brown sugar and ½ cup white sugar using a mixer on medium speed for 2-3 minutes until light and fluffy. This incorporates air for tender cookies. Scrape sides often for even mixing.

2-Second Step: Add eggs and vanilla. Beat in 2 eggs one at a time, then mix in 2 tsp vanilla extract. Continue beating for 1 minute. The mixture should look smooth and creamy. If lumps appear, beat longer. This step builds emulsion for better dough cohesion.

3-Third Step: Combine dry ingredients. In a separate bowl, whisk 2¼ cups flour, 1 tsp baking soda, and ½ tsp salt. Gradually add dry mix to wet ingredients on low speed. Mix just until combined, about 1 minute. Avoid overmixing to prevent tough cookies.

4-Fourth Step: Fold in mix-ins. Gently stir in 1 cup toffee bits and ½ cup chocolate chips by hand with a spatula. The dough will be soft and sticky. For extra flavor, lightly toast toffee bits in a dry pan first, then cool completely before adding.

5-Fifth Step: Chill the dough. Cover bowl and refrigerate for 30-60 minutes. Chilling prevents spreading, ensures thick cookies, and intensifies flavors. Scoop 2-tablespoon portions into balls meanwhile.

6-Sixth Step: Shape and fill cookies. Place dough balls 2 inches apart on prepared sheets. Press thumbprint into each center. Fill indent with 1 tsp salted caramel sauce. If store-bought, microwave briefly to loosen. Sprinkle flaky sea salt on top.

7-Seventh Step: Bake to perfection. Bake at 350°F for 10-12 minutes. Edges turn golden, centers stay soft. Rotate sheets halfway for even baking. Watch closely past 10 minutes to avoid overbaking.

8-Final Step: Cool and serve. Cool cookies on the tray for 5-10 minutes before transferring to a wire rack. They firm up as they cool, developing crisp edges and gooey centers. Enjoy warm with milk or coffee. Store extras properly for later.