Preheat the oven to 170 C. Grease a 20cm x 20cm baking pan. In a saucepan over medium heat, melt butter. Remove from heat and add 1 cup chocolate chips, but do not stir.
In a large bowl, beat eggs until foamy. Gradually mix in the sugar. Stir together the softened chips and butter, and blend into the egg mixture along with the almond essence. Combine the flour and salt; stir into the batter until just mixed. Spread half of the batter into the prepared pan.
Bake for 15 to 20 minutes in the preheated oven or until golden brown. In a small saucepan, over low heat, warm the jam to make it more liquid. Spread the jam over the warm crust. Stir the remaining cup of vanilla chips into the remaining batter, then drop the rest of the batter by teaspoonfuls over the jam. Sprinkle with almonds.
Bake for an additional 30 to 35 minutes in the preheated oven, or until a toothpick inserted into the center comes out clean. Cool in pan on a wire rack before cutting into bars.