In a medium bowl combine cocoa powder, all purpose flour, spelt flour and baking powder.
Combine butter and brown sugar in a heatproof bowl. Place the bowl over a pan of gently simmering water (double boileand mix until the butter is melted.
Let the mixture cool for few minutes and transfer it to a large mixing bowl. Add eggs and mix well, until combined. Add vanilla extract and mix shortly, until combined. Gradually add the dry ingredients, mixing gently with a wooden spoon, until absorbed. At the end add the oats and then the chocolate chips. Mix just until distributed in the dough.
Cover the bowl with cling film and let the dough chill in the fridge for 30-60 minutes.
Preheat oven to 350 degrees F (180 degrees C). Line two large baking tins with parchment paper.
Using an ice cream scoop make balls out of the dough and arrange them on the baking paper, not too close one next to another.
Bake for 10-12 minutes or until the cookies are just set but still very soft.
Let them cool on a wire rack.