Preheat oven to 180°C/350°F/Gas 4.

Spread whole almonds on a baking sheet into a single layer without overcrowding and place in the preheated oven for 5-6 minutes.

Remove the baking sheet from the oven and push the whole almonds to one side of the baking sheet, as shown. Pour the sliced almonds on the other side and spread into a thin, even layer. Return the baking sheet to the oven for another 4-5 minutes. Remove from oven and set aside.

Place the toasted whole almonds in a food processor and pulse until only a few larger pieces remain. Set aside.

Melt two tablespoons of butter in the microwave and set aside.

Create a sling (overhang) from parchment paper, as shown, and line an 8” x 8” baking pan with it. Pour the melted butter onto the parchment paper and spread evenly across the bottom and the sides of the baking pan.

Sprinkle half of the ground almonds onto the greased parchment paper, as shown, in an even layer and set aside.

Pour one-half cup of chocolate chips into a microwave-safe bowl. Microwave on high, stirring every 20-25 seconds until completely melted. Remove from microwave and pour the melted chocolate over the ground almonds. Spread into an even layer with a spatula and place in the refrigerator just until set.

Add the remaining chocolate chips to the food processor and pulse until chopped small. Set aside.

Place a large, heavy saucepan over medium heat. Add remaining butter, sugar, water, and corn syrup and stir continually for 5-6 minutes until the butter is completely melted.

Stop stirring and add the candy thermometer to the saucepan (without touching the bottom) once the mixture begins to bubble. Reduce heat to just below medium and continue to cook until the mixture reaches between 290°F - 295°F/143°C-146°C (hard crack stage).

Remove from heat and immediately stir in the vanilla extract and baking soda. Pour mixture into the prepared baking dish and gently tap on the counter until the hot candy mixture is level.

Add the ground chocolate chips in an even layer across the top and spread with a spatula until melted and smooth, as shown.

Sprinkle the remaining ground almonds in an even layer on top, and finish with the toasted sliced almonds. Tip: Press down gently with your fingers to make sure the almonds adhere to the layer of chocolate.

Place in the refrigerator for 10-15 minutes, or just until set.

Remove from the refrigerator and lift the parchment paper from the pan. Place the candy on a cutting board and carefully break it apart with the tip of a sharp knife into individual pieces as shown.

Serve immediately or store in an airtight container in the refrigerator for up to 3 weeks. Enjoy!