Preheat the oven at 350°F.
Sift flour and cocoa powder together in a bowl.
Mix in all other dry ingredients (baking soda, cinnamon powder, sugar and salt).
Set aside.
Add water, oil, lemon juice and cocoa essence to a separate bowl.
Whisk thoroughly.
Pour the wet ingredients over the dry ingredients.
Whisk to combine until smooth.
Pour the batter into a floured and buttered cake pan (9 inch works well).
Sprinkle chocolate chips onto the batter (optional).
Bake for 30 to 35 minutes.
Remove from heat and set aside to cool.
Add icing or frosting if desired before serving.