Mix together the caster sugar and golden syrup in a medium size saucepan until it forms a crumb. While stirring, allow the sugar to dissolve at a medium heat. Once dissolved, leave to gently bubble for approximately 4 minutes.
Remove the saucepan from the heat and immediately fold through the baking soda. Be careful not to overmix, then quickly turn out onto a baking tray lined with grease-proof paper before the mixture solidifies.
Allow to cool, harden and set aside.
Preheat oven to 200°c bake and line a square 20cm tin with baking paper.
Melt and mix together the butter and dark chocolate in a medium sized saucepan. Once melted and combined, remove from heat and allow to cool.
While butter is cooling, mix together the flour, baking powder, cocoa powder and salt in a bowl then set aside.
When butter has cooled slightly, beat in the sugar, vanilla and egg until smooth. Add the dry ingredients and fold though until combined.
Pour mixture into prepared baking tin and bake for 11-12 minutes or until the top has set. Then place the tin straight into the fridge to stop it baking further.
Using a food processor, blitz the hardened hokey pokey until it resembles a fine powder, then set aside.
In a small bowl or ramekin, dissolve and mix together the gelaine with 2 tablespoons of boiling water, then also set aside.
Add the cream cheese and sour cream into a large bowl and whip with a handheld beater until smooth. Gradually add in the hokey pokey powder and gelatine mixture, continuing to beat through until smooth and well incorporated.
Pour the cream into a medium sized jug and whip until soft peaks form. Fold the whipped cream through the cream cheese mixture until just combined.
Pour cheesecake filling over top of prepared brownie base, cover and chill in the fridge for 4-6 hours or overnight. Once set, remove from tin, slice and enjoy.
In a medium sized bowl, add the dark chocolate and cream and microwave with 10 second bursts until chocolate has melted enough to mix smoothly together.
Allow to cool, then either using a piping bag with nozzle or squeezing bottle with nozzle, pipe lines or drizzle pattern over top of cheesecake.
Return to chill in the fridge or decorate before serving.