At some point I’ll test this, but I’m guessing 350F for the oven temperature. While that’s a bit lower than I’d normally think (most brownies would need to be at 400 to cook in 20 minutes), if we’re genuinely spreading this only a third of an inch thick, it won’t take quite that much heat.
From a box sold in San Antonio, Texas.
2 cups flour
1/2 cup shortening
2 cups sugar
1 cup chopped pecans
1/2 cup water
1/2 tsp. baking powder
1 tsp. vanilla
2 squares unsweetened chocolate
Add pecans last.
Spread in shallow baking pan one-third inch thick. Bake 20 minutes in slow oven. Cut in squares and remove from pan while hot.
Yesterdish suggestion: See the note at the top, but my guess is 350 deg. oven.