The short routine ended with Amanda walking behind a bush in her garden, giving fans a glimpse of her pert bottom.
The Britain’s Got Talent judge shared the video on her TikTok and Instagram pages.
In view of her 1.5 million followers, she wrote: “Well… what else is there to do in a power cut in the rain??!”
Many of the star’s fans flocked to her post to comment, including her long-term friend Piers Morgan, who shared a series of crying with laughter emojis.