Preheat oven (electric cooker: 180 °C/circulating air: 160 °C/gas: see manufacturer). Line a square springform pan (24 x 24 cm; alternatively round, 26 cm Ø) with baking paper. Chop the cranberries. Melt margarine and peanut butter in a pot. Stir in sugar, syrup, cranberries and oat flakes. Spread the mixture in the mould and press it down.
Bake in a hot oven for about 20 minutes, covering with baking paper after about 15 minutes if necessary. Remove from the oven and let cool off lukewarm.
Chill the muesli cake for about 3 hours. Carefully remove from the mould and cut into approx. 24 strips.
For 2 glasses (approx. 200 g each): 400 g roasted peanut kernels and 1⁄2 puree TL sea salt in a high performance floor mixer until creamy. Pour into hot rinsed glasses. Close tightly with lids. Keep refrigerated for approx. 4 weeks.