Leave butter at room temperature. Cut baking sheet to get three sheets.
2
Sheets: Sip the flour and put it in the bowl. Add baking powder, sugar, egg, butter and milk and knead until even. Separate the dough in three (two bigger 150g, one smaller 80-90g).
3
Using rolling pin spread one bigger part to the size of the baking sheet. Repeat the same with other bigger part and then with smaller part. Put two big sheets on the opposite side of baking tray and bake in the preheated oven 180C for 6min.
4
When it’s done repeat with remaining smaller sheets. Cut two bigger sheets in half so you have, together with smaller one, 5sheets of same size. Cut the uneven parts of sheets.
5
Cream: Sip the flour and mix it with cocoa powder, then add around 200ml of milk, the rest of the milk put in the separate pot at the stove to boil together with sugar.
6
After sugar is melted lower heat, add the flour/cocoa mixture slowly and mix constantly for few minutes until the cream is like pudding. Turn off the heat, add butter and stir it well.
7
Glaze: Using double boiling system, melt the chocolate with oil.
8
Place first sheet on the tray and spread 1/4 of the cream evenly. Repeat the process with 4 remaining sheets, putting one on top another. Press gently on top with your hands.
9
When the glaze is melted and ready put it on the top of the last sheet evenly. Shake it a bit so the glaze spread evenly. Put in the fridge to cool down.
10
When glaze is cooled down a bit you can take the cake out of the fridge and cut just the glaze part is small even squares and put it back to the fridge.
11
That can prevent the glaze from breaking when you cut the cake later. Cake is ready to eat after several hours or even better the next day.