• Preheat the oven to 350°F (180°C) and line an 8x8 inch pan with parchment paper. leave an overhang so you can easily lift the baked cookies out.
• Cream together the butter, brown sugar, and granulated sugar until light and fluffy. Mix in the molasses, eggs, and vanilla until well combined.
• Whisk together the dry ingredients and add to the wet mixture and combine it into a thick dough.
• Spread the dough evenly into the prepared pan. Bake for around 25 minutes, until the edges are set. Let cool completely.

Ganache

• Add chopped white chocolate to a heatproof bowl.
• Heat heavy cream, lemon zest and lemon juice in a small saucepan until it just begins to simmer. The lemon juice will thicken the cream a bit, that's normal.
• Pour this over chopped white chocolate and let sit for 2–3 minutes, then stir until smooth.
• If the white chocolate doesn’t fully melt, place the bowl over a pot of simmering water (double boiler) and gently stir until smooth. Alternatively, microwave the mixture in 5-10 second intervals on low power, stirring in between, until fully melted.
• Once the ganache is made, let it cool and thicken a bit before using.

Assembling

• Spread the ganache evenly over the cooled gingerbread bars.
• Allow it to set at room temperature or chill in the fridge to cool it faster.
• Slice into squares or rectangles and enjoy!