A ritual dish
Early sources mention the pancake primarily as festive and ritual food. It was baked at Maslenitsa — the week before Great Lent — and a round, hot pancake read as a sign of the sun and the coming spring. The batter was leavened with yeast, often as a sponge starter, and baked in a Russian stove: heat came from above and below, so the pancake turned out fluffy rather than thin.
Wheat flour was expensive, and everyday cooking more often used rye, oat or buckwheat flour. Hence the range of flavors that today seems "authorial": buckwheat pancakes were ordinary food, not a gastronomic rarity.