Strawberry Cream Cake (jordgubbstarta)

Preheat oven to 170°C. Using electric beaters, whisk together eggs and sugar in a large bowl until thick and pale. Sift flour and baking powder into another bowl. Combine milk, butter and vanilla extract in a jug. Alternate folding dry ingredients and milk mixture into egg mixture in 3 batches, until just combined.
Grease a 20 cm-round cake pan with extra butter. Scatter with breadcrumbs, shaking pan to coat base and sides evenly and discarding any excess. Pour cake batter into prepared pan, then bake for 40 minutes or until a skewer inserted in centre comes out clean. Cover with foil if cake is browning too quickly. Cool in pan for 5 minutes, then transfer to a wire rack to cool completely.
Using a serrated knife, cut cake in half horizontally. To assemble, place bottom half on a plate or cake stand. Spread with custard, then top with half the cream, sliced banana (if using) and sliced strawberries. Sandwich with remaining cake half, then, using a spatula, spread remaining cream over top and sides. Decorate with halved strawberries and serve.