Pour buckwheat into a saucepan, add 1.5 cups of water, salt and put on the fire. When the water boils, reduce the heat to low and cover the saucepan with a lid. Cook the buckwheat over low heat under the lid for about 15 minutes until the water is completely absorbed.
Cut the apples into small 1 cm cubes.
In a deep bowl, combine buckwheat, apples and jam.
Add flour and baking powder. Mix everything thoroughly.
Grease a baking dish with vegetable oil, place the buckwheat mixture in it and smooth it out with a spatula.
Place the casserole in the oven for 20-25 minutes. Remove when ready.
Garnish the finished dish with a slice of fresh apple.