Peanut butter and jam doughnuts

Dough

• oil, for greasing
• 140 g full cream milk
• 1 tbsp caster sugar
• 2 tsp dried instant yeast
• 270 g baker's flour
• 30 g salted butter, melted
• ½ tsp ground cinnamon
• 1 tsp salt
• 1 egg
• 120 g strawberry jam
• 500 g water

Peanut butter glaze

• 50 g roasted salted peanuts, plus extra for decorating
• 100 g dark chocolate, broken into pieces
• 80 g icing sugar
• 20 g full cream milk
• 150 g smooth peanut butter (see Tips)
• ½ tsp natural vanilla extract
• cinnamon sugar, for dipping