- In a large bowl, add the warmed milk, sugar and yeast. Whisk and let sit for about 5 minutes to let the yeast bloom.
- Add the eggs and vanilla. Whisk to combine. Add the flour, lemon zest and salt. Stir to combine. Then add the butter and mix until smooth. Cover with a cloth until doubled in size.
- Punch dough down slightly. Divide the dough into 70g balls, roll tightly. Transfer the rolls to a tray and cover, let rise until doubled in size.
- Heat oil to 170ºC. Fry donuts on each side until golden brown.
- Let cool slightly on a rack then toss in sugar to coat, then cool completely.
- Place strawberries and sugar in a small saucepan over low heat. Cook, stirring, for 3 minutes or until sugar has dissolved. Cover. Simmer until the mixture has thickened slightly and strawberries are starting to break down. Stir in lemon juice.
- Mix cornflour with 2 tsp water in a small bowl. Add cornflour mixture to strawberry mixture. Cook, stirring, for 1 minute or until mixture boils and thickens. Remove from heat and let the mixture cool completely.
- In a pot, add sugar, cornstarch, eggs, and vanilla. Whisk to combine. Gradually whisk in milk. Bring to medium heat and whisk continuously until mixture thickens. Add the butter and mix to combine. Remove from heat and let cool completely.
- Meanwhile, whip cream with icing sugar until stiff peaks form. Fold the whipped cream into the cooled pastry cream mixture until combined.
- Keep in the fridge until ready to use
- Cut a slit in each of the donuts in the middle using a sharp knife. Fill each donut, one half with the pastry cream and the other with strawberry jam. Top with strawberry slices.