Step 1

Grease a 4cm-deep, 17 x 27cm (base measurement) slice pan. Line the base and 2 long sides with baking paper, allowing the long sides to overhang.

Step 2

Finely chop one-quarter (about 65g) of the speckled eggs. Break the biscuits into a food processor and process until fine crumbs form. Transfer to a bowl. Add the butter and stir until well combined. Stir in the chopped eggs. Spoon into the prepared pan. Use a flat-bottomed glass to press the mixture evenly over the base. Place in the fridge for 20 minutes to chill.

Step 3

Meanwhile, place 60ml (1/4 cup) water in a small heatproof bowl. Sprinkle with the gelatine and stir until well combined. Place the bowl inside a larger heatproof bowl. Pour boiling water into the larger bowl until it reaches halfway up the side of the smaller bowl. Set aside, stirring occasionally, for 5 minutes or until the gelatine dissolves.

Step 4

Use electric beaters to beat the cream cheese, sugar and 1 teaspoon vanilla until smooth. Gradually add the cream. Beat until combined. Add the gelatine mixture and beat until combined. Tint the mixture pale blue with the colouring. Pour cream cheese mixture over the biscuit base. Smooth the surface. Place in the fridge for 6 hours or overnight until set.

Step 5

Combine the cocoa and remaining vanilla in a small bowl. Cover the floor and bench with a drop sheet or newspaper. Dip a small, stiff pastry brush or unused paint brush into the speckle mixture and flick over the slice to create a speckled look. Place the slice in the fridge for 15 minutes to chill.

Step 6

Use baking paper to carefully lift the slice from the baking pan. Decorate with remaining speckled eggs. Use a small sharp knife, dipped into warm water and wiped dry, to cut into pieces to serve.