indeed, i could

• open https://minecraftcirclegenerator.co/
• put firefox in second monitor
• go in gimp, select pixel brush
• draw the circle pixel by pixel
• draw the inside of the circle, pixel by pixel, just as before
• go back to https://minecraftcirclegenerator.co/
• get a slightly smaller circle
• draw that circle pixel by pixel with the same color as the background
• draw the inside of the new circle pixel by pixel with the bg color