Melt the butter, syrups and brown sugar in a saucepan. Place all the dry ingredients into a mixer, on a low speed, and combine them. Add the wet ingredients and mix until incorporated. Finish with the egg and beat for 5 minutes, until smooth and pale. Bake in a lined cake tin, at 325°F/160°C, for 45-50 minutes. Cool and then cut into 1" cubes.
Make the Strawberry Jelly
Sprinkle the strawberries with a bit of sugar and mix. Let sit overnight then press the strawberries through a sieve to make juice. You should have 2/3rd cup.
Mix the gelatin in 1/4 cup water. Add the strawberry juice, mix well then strain.
Start Assembly
Place 3 roasted strawberries in the bottom of a glass with the diced parkin. Add about 1/2 cup of strawberry jelly into a large trifle bowl or individual glasses and transfer to the fridge, to set.
Make the Ginger Custard
Place the milk and ginger into a saucepan and heat until just before it reaches the boil. Remove from the heat and leave to the side to infuse for 20 minutes. Whisk the egg yolks and the sugar together, add the cornstarch then pass the infused milk through a fine sieve into the egg mixture. Whisk together and then transfer back into the saucepan. Place the saucepan back on the heat and whisk continuously, until the custard reaches 85°C and thickens. Transfer to a tray and cover with greaseproof paper, to cool.
Make the Cream
Add the icing sugar and vanilla seeds to the cream. Whip the cream to stiff peaks, then transfer to a piping bag for serving.
Candied Pistachios
Pre-heat the oven to 170°C. Place the nuts on a baking tray and toast, in the oven, for 12 minutes. Pour the water and sugar into a small saucepan. Place it over a medium-high heat and bring it to the boil. When the temperature of the liquid reaches 135°C, or the syrup is beginning to colour at the edge of the pan, add the pistachios and whisk until the syrup has completely crystallised and coated the nuts. Pour the coated nuts onto a baking tray, lined with greaseproof paper, and allow to cool.
Assemble for Serving
Pipe a layer of ginger custard onto the top of the jelly. Pipe dots of the cream on top, until the whole glass is covered. Add the candied pistachios on the top, to finish.