Melt butter in a pan or dish and set aside to cool for a minute.In a large bowl, combine sugars, butter, eggs, cocoa, salt, espresso, and vanilla. Slowly fold in einkorn flour until combined.
Fold in chocolate chunks.Pour into a greased or parchment lined 9x13 baking dish, spreading the batter evenly throughout the pan. Bake for 30 minutes. The edges should be starting to get crispy and the middle should be soft, but set.
Notes
Chocolate chunks are way better than chips. Yes, this may just be my opinion, and chips will work just fine, but there is just something extra decadent about the chocolate chunks.
Espresso is optional, but this addition to the brownie results in a richer chocolate flavor.