Mix the flour, baking powder and salt. Layer all ingredients, starting with the sugar, then cocoa, then flour and finally the nuts, in a mason jar and seal.
Attach the following instructions to the glass: 1. Fill the glass with the brownie mix into a large bowl. Stir well. 2. Then add 175 grams of melted margarine and three eggs, previously beaten lightly. 3. Stir until the dough is smooth. 4. Pour the dough into a large, square or round, greased baking tin. About two to three centimeters high, not higher! 5. Bake brownies at 175 degrees for about 30 to 40 minutes. Let cool completely and then cut into square pieces