Preheat the oven to 180ºC, fan 160ºC, gas 4. Line a 31cm x 23cm tin with baking paper.
In a large bowl, mix together the oats, ginger, lemon zest, dried fruit and seeds and set aside.
Heat the condensed milk, spread and vanilla extract in a small pan over a low heat, stirring occasionally until combined. Pour into the bowl with the dry ingredients and stir well.
Spoon the mixture into the tin, spread evenly and bake for 25 minutes.
Remove from the oven, allow to cool completely, then cut into 24 bars. You can store in an airtight container for up to 4 days.