Melt butter in a saucepan over medium heat. Cook, stirring occasionally, until it turns golden brown and gives off a nutty aroma. Remove from heat and let it cool.

In a medium bowl, whisk together flour, cinnamon, and salt. Set aside.

In a large bowl, cream together cooled browned butter, brown sugar, and granulated sugar until light and fluffy. Beat in eggs one at a time, then stir in vanilla extract.

Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Stir in brewed coffee, instant coffee granules, and toffee bits.

Cover the bowl and refrigerate the dough for at least 1 hour or up to 3 days.

Preheat oven to 350°F (175°C). Line baking sheets with parchment paper or silicone baking mats.

Using a cookie scoop or spoon, drop rounded dough balls onto the prepared baking sheets, leaving about 2 inches between each cookie. Sprinkle with additional sea salt if desired.

Bake for 10-12 minutes, or until the edges are golden brown and the centers are set. Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.