Whisk all of the wet ingredients plus the ground flaxseeds together until smooth.
Add the dry ingredients directly on top of the wet ingredients and gently fold the mixture until just combined.
Pour the batter into a lined loaf tin. If using, soften (not fully melt) the extra biscoff spread in the microwave for a few seconds, spoon onto the batter and swirl through with a knife or skewer.
Bake in preheated oven at 175°C for about 45-55 minutes or until a knife entered into the middle comes out clean.
When cooled, slice and drizzle with more biscoff spread.
I followed it exactly as written and it turned out perfectly.