Step 1: Brown the Butter - In a saucepan over medium heat, melt the 1/2 cup unsalted butter. Continue cooking, stirring frequently, until the butter turns a golden brown color and develops a nutty aroma. Be careful not to burn it! Once browned, remove from heat and let it cool slightly.
Step 2: Mix the Wet Ingredients - In a mixing bowl, combine the browned butter and 1 cup light brown sugar. Whisk together until well combined. Add in the 1 large egg and mix until smooth.
Step 3: Combine Dry Ingredients - In another bowl, whisk together the 1 cup all-purpose flour, 1/2 teaspoon cinnamon, and 1/4 teaspoon salt.
Step 4: Combine Wet and Dry Mixtures - Gradually add the dry ingredients to the wet mixture, stirring until just combined. Be careful not to overmix.
Step 5: Fold in the Goodies - Gently fold in the 3/4 cup toffee bits, 1/2 cup chopped espresso beans, and 4 ounces chopped semi-sweet chocolate until evenly distributed.
Step 6: Bake - Preheat your oven to 350°F (175°C). Line your 8x8 inch baking pan with parchment paper for easy removal. Pour the batter into the prepared pan and spread it evenly. Bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
Step 7: Cool and Serve - Allow the blondies to cool in the pan for about 10 minutes, then lift them out using the parchment paper and let them cool completely on a wire rack. Cut into squares and serve!