1- First of all, put your all ingredients on your kitchen container. Firstly, wash your spinach well and then rip the stems off the leaves and put all of them in a colander. With boiling water from a Kettle let them get soft and squeeze out the liquid. Then blend softened spinach into blender (we can get 1 Cup Spinach Puree from 1,5-2 Cups Fresh Spinach).
2- For the cake: Mix eggs with granulated sugar and vanilla extract until creamy (until they turn to white and frothy). Then, add the milk and vegetable oil and whisk. Then, add the spinach puree and whisk. After these processes, add the flour and baking powder, then stir until you get a smooth batter. Then, place parchment paper into your cake-pan/30 cm cake-pan (or place parchment paper into your cake mold and lock it) and pour mixture into a cake-pan. Bake at 180°C (350°F) oven until a toothpick inserted in the center of cake and comes out clean (nearly 45-50 minutes). Then, remove from oven and let it cool completely before inverting on a platter.
3- For the custard: Stir the milk, granulated sugar, starch and vanilla in a pot. Then, cook mixture until it thickens by stirring constantly. Then, remove the pot and let it get warm. Then add the whipped cream and a handful chocolate chips and mix for 15 minutes.
4- Then, flatten the top of the cake by using an knife (This separated part will also be used to cover the top of the cake, also trim half a centimeter from the sides). Then, cut the cake in half, so you can get two half pieces, and spread some of the custard mixture on top of the first layer, then place the second layer on top. Then, spread the rest of the whipped cream mixture on top and on the side of the cake. Now, crumbled the trimmed cake pieces and cover the top of the cake with them.
5- This spinach cake can be served cold or room temperature. if you want, you can place into refrigerator for a while (1 or 2 hours).