Preheat oven to 350 degrees. Cut out the parchment paper liners for the number of layers you are making. Grease the sides of your cake pans so the baked layer will easily come out of the pan.

Beat butter until cream and then add sugar, vanilla, eggs and salt.

Mix the flour, corn starch and baking powder to the butter mixture 1 Tbsps at a time. It should take about 4 minutes of beating to add all the dry ingredients. Batter will be very thick.

Divide the batter evenly for the number of layers you are baking. Spread batter evenly over the parchment paper templates ensure the batter does not thin out at the outer edges.

Reduce the oven temperature to 325 degrees when you put the cake pans in. Bake 8-10 minutes if you are making 4 or 5 layers or until a toothpick comes out clean from the center. Do not let the edges get crisp and brown so check after 8 minutes.

If you are making deeper layers that you plan to cut in half then the baking may take 25-30 minutes. Check after 25 minutes and bake until a toothpick comes out clean from the center.

Invert baked cake layers to a wire rack to cool and gently remove parchment paper immediately.

Repeat until you have the number of layers baked that you want.

Cool completely before filling and icing.

Mix the pudding powder, cocoa and sugar together. Add the milk and beat for about 4 minutes. Allow pudding mix to stand about 5 minutes to thicken.

Beat in the butter. Mixture will be grainy. Mix it well. Then microwave the mixture on High for about 2 minutes until the butter melts into the mixture. You may have to heat a bit more depending on the power of you microwave. Do not overheat. Beat mixture after the butter has melted in until it is silky smooth.

Chill the filling to allow it stiffen up.

Melt chocolate gently. I set a heat proof bowl in a skillet of water over medium heat and stir until the chocolate is melted. Add the vegetable oil and mix evenly. Remove from heat.

Place the bottom layer of your cake on your foil template preferably over a wire rack so any excess filling or icing can drip down through the rack.

Spread filling evenly over the first layer. Repeat with the remaining layers but do not put filling on the top layer. You may have some filling left over.

Pour warm icing over the top layer. Smooth out with an offset spatula and let it drip over the sides. Add icing to the sides as needed to completely cover the sides.

Transfer the cake to serving plate and decorate with whipped cream fresh fruit and/or chocolate shavings.

Refrigerate about 4 hours to allow flavours to meld. Can be made a day or 2 ahead. Keep chilled. Serve additional fruit and whipped cream on the side if desired.