Preheat oven to 350 degrees. Line a 9X13 baking dish with parchment paper. Combine melted butter, brown and white sugar in a bowl. Mix with spoon. Next add in, eggs, vanilla, salt, baking powder and flour.
Continue to mix with a spoon until combined. Next fold in toffee bits and pecans. I didn't use a mixer when I made this and it worked really well.
Next press mixture into your 9X13 dish. I sprinkled extra pecans and toffee bits on top. Bake for 30 minutes or until center test done. These are a mixture between a brownie and a piece of cake.
Notes
You could also use a Heath candy bar crushed up if you have trouble finding the toffee bits.