Chocolate hazelnut cake slices

Pour the hot prepared coffee over the semi-sweet chocolate to melt it, or use a heaping teaspoon of instant coffee with one and a half cups of water. Mix and set aside to cool.

Whisk the flour, cocoa powder, baking powder and salt together.

Mix the granulated sugar, oil, room temperature eggs and vanilla extract.

Add the yogurt, baking soda and milk and mix, then the chocolate and coffee mixture, then the dry ingredients a little at a time until combined.

Line two half sheet baking trays with parchment paper and spray the parchment.

Distribute the batter evenly between the two pans, about 10 ice cream scoops per pan, and spread it into a thin even layer.

Bake at 350F on two racks; the upper tray is done at around 22 minutes and the lower at about 25 minutes total.

Cool completely, transfer onto plastic wrap, remove the parchment from the back, wrap, stack on a baking tray with parchment between the layers and freeze well. Keeps two to three months frozen.

Pastry cream: combine four cups whole milk, one cup granulated sugar and a pinch of salt in a saucepan.

Whisk half a cup granulated sugar, eight egg yolks, half a cup heavy whipping cream and eight tablespoons cornstarch until smooth.

Once the milk is steaming hot, whisk it into the egg mixture to raise their temperature, return everything to the saucepan and bring to a boil, stirring constantly.

As soon as it boils it thickens. Take it off the heat and stir in three to four teaspoons of vanilla extract.

Transfer to a big bowl, cover with plastic wrap against the surface so it does not skin, and cool completely. Keeps refrigerated two to three days.

Syrup: combine one cup granulated sugar, one cup water and one to two teaspoons instant coffee in a saucepan, whisk and bring to a boil.

Once the sugar dissolves, take it off the heat, add one teaspoon vanilla extract and cool completely. Keeps refrigerated up to a week.

Bring the pastry cream to room temperature, whisking it smooth; hot pastry cream melts the butter and cold pastry cream makes it seize.

Beat one pound of soft unsalted butter with a pinch of salt and two teaspoons vanilla extract on the whisk attachment until broken up and smooth.

Add one cup confectioner's sugar and beat until fluffy, scraping down the sides.

With the mixer running, add half the pastry cream a little at a time, then mix on high, scraping down, until soft and fluffy.

Divide the cake into two equal layers, working on the back of a half sheet pan with parchment on top. Keep the cake chilled or it falls apart.

Brush the first layer generously with the coffee syrup.

Pipe a border of frosting around the edge of the cake to hold the filling in and level the layer.

Spread chocolate hazelnut spread inside the border, enough that it does not lift the crumbs, then a layer of buttercream. Strawberries can go on before the buttercream, or a layer of the remaining pastry cream instead of buttercream.

Add the second layer, brush it with coffee syrup concentrating on the drier edges.

Frost the sides by piping close to the cake or spreading with an offset spatula, then spread icing over the top and smooth the sides.

Snip the tip off a piping bag of chocolate hazelnut spread and pipe diagonal lines across the top; or melt it in the microwave and swirl it with a knife or spoon.

Freeze 15 minutes to set.

Cut into slices, four inches on the eight inch side and two inch increments on the twelve inch side, cleaning the knife with a damp paper towel between cuts or wetting it under hot water.

Sit each slice in a large cupcake liner, pipe a rosette on the top back end and top with halved strawberries.

Variation: to freeze, pipe the rosettes but skip the berries, freeze solid, then wrap tightly; keeps about two months. Thaw on the counter about 30 minutes.