Sold Earthenware baking dish in blue with dots, vintage

Sold A vintage earthenware bowl with medium blue glaze layer with cream dot decoration. You can use the vintage bowl for all kinds of purposes. Use it as an oliebollen bowl, as a salad bowl, as a fruit bowl, etc. The earthenware bowl in medium blue is marked at the bottom with an oval ring resembling a spider with the number 9. Is it part of Bunzlau?