Place the apricots, lemon juice, vanilla, cardamom and gelling agent in a pan, bring to the boil while stirring, boil fast for approx. 1 min. Add the sugar, cook for another 4-6 mins. while stirring. Skim off any foam. Test to see if the jam has set by spooning a small amount of the hot jam onto a plate and leaving it to cool. If it is no longer runny and forms a thin skin after a short while, it has achieved the right consistency. If not, continue to boil briefly and then test it again. Stir in the flaked almonds, ladle the jam into the clean, pre-warmed jars while still boiling hot, fill the jars to just below the rim, seal immediately.