Chocolate Slice with Macaroon Topping

I found this recipe for a Chocolate Slice with Macaroon Topping while looking for a way of using up three egg whites. I knew I wanted a chocolate element in the recipe, as part of the traybake was being given to my son, who is a chocoholic like me, and I think the idea of almond macaroons was floating in my subconsciousness as I'd recently made a frangipane topped tart. If I hadn't found this recipe, I would eventually have combined parts of other recipes I've used in the past to make something very similar - perhaps with a chocolate shortbread base.

I made a few adaptations to the recipe, both to cater for what was in the store cupboard and to avoid using more than one extra egg, which would then create more leftovers. This meant that I cracked one more egg to get 4 egg whites, then used the yolk and 2 tablespoons of milk in the chocolate layer, instead of a whole egg. I also used less jam between the chocolate base and the macaroon topping, and missed out the white chocolate chips altogether. Obviously I haven't tasted the original recipe, but I don't think this slice suffered from losing the sometimes sickly sweetness that white chocolate brings to already sweet enough recipes.

Ingredients
for the base:
125g unsalted butter, at room temperature
150g plain flour
pinch salt
3 tablespoons cocoa
60g icing sugar
1 egg yolk
3 tablespoons milk
1 teaspoon vanilla extract
100g apricot or raspberry jam, warmed slightly
( I had to use a mixture of apricot jam and marmalade to get this amount of jam, and sieved the mixture after warming to remove pieces of apricot and orange peel)

for macaroon topping
4 egg whites
150g ground almonds
150g caster sugar
a few drops of almond extract
flaked almonds for sprinkling

Method
Preheat the oven to 170C and line a 20cm(8") shallow square baking tin with parchment, making sure the paper covers the sides of the tin too.
Place all the ingredients for the base, except the jam, into a bowl, sifting in the flour, cocoa and icing sugar to avoid clumps. Beat with an electric mixer until smoothly combined, then spread the batter evenly into the baking tin. Bake for 15 minutes until firm.
Cool for 5 minutes, then spread with the jam.
Increase the oven temperature to 180C.
Make the topping by whisking the egg whites to the soft peak stage, then fold in the ground almonds, sugar and almond extract.
Pour this mixture over the base and sprinkle with flaked almonds. Bake for 25-30 minutes, until top is golden and firm.
Cool in the tin before cutting into bars.

This was really delicious; definitely something to make again! The chocolate base was somewhere between a cake and a biscuit in texture. It wasn't very sweet either, which provided a good contrast to the sweet, chewy macaroon topping, and the jam between the layers.

Unfortunately, the slice was cut, wrapped and delivered to my children before I had time to look at the photographs, so I've only got good photographs of one of the two pieces I kept, so that we could taste it too.