Preheat the oven to 350°F.

Line an 8-inch square baking pan with enough foil so that the foil extends a few inches over 2 sides of the pan (this will make it easy to lift the brownies out after baking).

Butter the foil.

Put chocolate and butter in a medium saucepan over low heat.

Cook, stirring frequently, until butter and almost all of the chocolate has melted, about 4 minutes.

Turn off the heat and let the mixture cool for a few minutes (any remaining chunks of chocolate should melt).

Turn off the heat and let the mixture cool for a few minutes (any remaining chunks of chocolate should melt).

In a small bowl, whisk together flour, chile powder, cinnamon, baking powder and salt.

Pour the chocolate mixture into a medium bowl and stir in sugar, eggs and vanilla.

Add flour mixture and stir just until smooth.

Pour into the prepared pan and bake just until the top of the brownies begins to look dried and a toothpick inserted into the center of the brownies comes out with moist crumbs but no raw batter sticking to it, 30 to 35 minutes.

Cool the brownies in the pan for 10 minutes and then use the foil on the sides to lift the brownies out and place on a rack to cool completely.

Peel off the foil and cut the brownies into 16 squares.

*Note that this recipe calls for ancho chile powder, made from ground chile peppers. Chili powder (which is made from a blend of seasonings) is not a substitute and will not yield good results.