Preheat the oven to 350°.
In a large bowl, combine cocoa and baking soda, whisk in the melted butter.
3/4 c. cocoa powder, 1/2 tsp. baking soda, 2/3 c. melted butter (approx. 11 Tbsp.)
Add the boiling water and stir until blended.
1/2 c. boiling water
Whisk in the sugar, eggs, and vanilla.
1 3/4 c. sugar, 2 large eggs, 1 tsp. vanilla extract
Add the flour and salt and stir to combine. Then stir in the pecans and chocolate chips.
1 1/3 c. all-purpose flour, 1 tsp. salt, 1/2 c. coarsley chopped pecans, 2 - 2 1/2 c. semisweet chocolate chips or chocolate chunks
Pour the mixture into a well-greased 9x13" baking dish.
Bake at 350° for 30 - 35 minutes.
Cool, cut into bars, and store in an airtight container. You can also freeze some to keep them fresh for later.