The invention relates to starch used in the baking industry. Creams, fruit fillings, toppings, glazes and other bakery products are often thickened by using starch as a binder, filling or thickening agent, thus providing gel-strength, viscosity, glaze, texture or creaminess to the cream or filling. Commonly used starches have insufficient stability to withstand heat applied during baking. The invention covers a starch-containing filling or topping for a bakery product in which the starch comes from a tuber or root and contains less than 5% amylase. Use of such a filling or topping for improving a bakery product is also covered by the patent. Furthermore, the invention provides a heat-stable starch and bakery products containing a heat-stable starch.