Preheat oven to 350°F. Line an 8"x8" pan with parchment paper.
Stir flour, cocoa powder, and salt together in a medium sized bowl.
Stir melted butter, sugar, and vanilla together in a large bowl. Then add eggs one at a time, stirring until just combined.
Add dry ingredients to wet ingredients and stir without overmixing - just until a few flour streaks remain. Fold in chocolate chips.
Pour mixture into pan and sprinkle remaining 1/4 cup chocolate chips on top.
Bake for 20-22 minutes if using teff or gluten free flour blend, or 15-20 minutes for buckwheat or whole wheat. A toothpick inserted in the middle will come out wet and a thin crust should have formed.
Let cool. Cover and store at room temperature, or refrigerate for fudgier texture.