<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
I want to make some brownies to take to work.
<|assistant|>
You will need: 1 1/2 cups all-purpose flour, 1 teaspoon baking powder, 1 teaspoon baking soda, 1/2 teaspoon salt, 1 cup butter, 1/2 cup unsweetened cocoa powder, 1/3 cup granulated sugar, 2 teaspoons pure vanilla extract, 2/3 cup chopped nuts (optional), 1/2 cup unsweetened chocolate (optional).

Instructions:
1. Preheat oven to 350°F. Grease a 9x9 inch baking dish.
2. In a medium bowl, mix together flour, baking powder, baking soda, and salt.
3. In a large bowl, beat the butter, cocoa, and sugar on medium speed until blended. Beat in the vanilla extract.
4. Add the dry ingredients and mix until blended. Beat in the nuts (if using). Stir in the chocolate (if using).
5. Spread the batter into the prepared dish.
6. Bake for 30-35 minutes until a toothpick inserted into the center comes out with few crumbs.
7. Cool on wire rack. Slice and serve!