Preheat the oven to 350°F (175°C) and prepare a 9×9-inch baking pan.

In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt.

In a separate bowl, cream softened butter and egg until light and fluffy. Gradually add brewed coffee, buttermilk, and vanilla, mixing well.

Slowly stir in dry ingredients until smooth.

Pour batter into the pan and bake for 25-30 minutes until a toothpick comes out clean.

Cool the cake in the pan for 10 minutes before transferring to a wire rack.

In a saucepan, combine brown sugar, butter, and heavy cream over medium heat. Stir continuously and simmer for 3-4 minutes until thick.

Remove from heat and stir in vanilla and a pinch of salt.

In a small bowl, combine brewed coffee and powdered sugar to make the coffee drizzle.

Poke holes in the cooled cake, pour warm caramel over it, and drizzle with coffee mixture.

Cut into squares and serve warm or at room temperature with whipped cream or ice cream.