Mix egg, egg yolk, sugar, and stabilizer until light and fluffy, add water, then slowly fold in the sifted dry ingredients (except chocolate powder) until combined.
Add melted butter and fold until incorporated.
Before adding chocolate powder, set aside a little portion of batter in a separate bowl to create a heart pattern.
Prepare a 30 x 40 cm baking pan lined with baking paper, create a heart pattern using the batter set aside earlier. This process must be done quickly to prevent the batter from deflating.
After creating the heart pattern, bake in the oven for 1 minute at 200°c.
