In a small saucepan, melt 1/2 cup butter over medium heat, stirring occasionally. Continue cooking the butter until it turns golden brown and smells nutty, about 5-7 minutes. Remove from heat and allow it to cool slightly.
1/2 cup butter
In another saucepan, combine the 1/4 cup butter and 1/2 cup brown sugar over medium heat. Stir continuously until the mixture melts and thickens, about 3-4 minutes. Add 1 tsp salt and stir until combined. Pour the toffee mixture onto a parchment-lined baking sheet, spreading it thinly. Let it cool and harden for about 10-15 minutes before breaking it into small pieces.
1/4 cup butter, 1/2 cup brown sugar, 1 tsp salt
In a large mixing bowl, combine the browned butter and 3/4 cup brown sugar, whisking until smooth. Add the 1 tsp vanilla extract and 1 egg and stir well. In a separate bowl, whisk together the 3/4 cup all-purpose flour, 1/2 tsp baking powder, 2 tsp salt, and 1/2 tsp cinnamon.
3/4 cup brown sugar, 1 tsp vanilla extract, 3/4 cup all-purpose flour, 1/2 tsp baking powder, 2 tsp salt, 1/2 tsp cinnamon, 1 egg
Gradually add the dry ingredients to the wet mixture, stirring until combined. Fold in the 1 cup old-fashioned rolled oats and chopped 5 graham crackers, ensuring everything is well mixed.
1 cup old-fashioned rolled oats, 5 graham crackers
Gently fold in the broken pieces of homemade toffee into the cookie dough.
Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. Scoop tablespoon-sized balls of dough onto the sheet, leaving about 2 inches of space between each cookie. Transfer the sheet to the fridge and chill for 30 minutes.
Bake for 10-12 minutes, or until the edges are golden but the center is still soft.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.