Act as a seasoned graphic designer with 10+ years of experience in crafting retro-themed logos. Design a vibrant, nostalgic logo for a [family-owned donut shop] named [Sweet Circle Donuts]. The logo should feature bold, rounded typography reminiscent of the 1950s, paired with a whimsical illustration of a [classic glazed donut with rainbow sprinkles]. Use a warm color palette with shades of pink, yellow, and teal to evoke a cheerful, retro diner vibe. Incorporate subtle elements like a retro badge or banner to highlight the shop's tagline: 'Handcrafted Happiness Since 1962'. Ensure the design is clean, scalable, and instantly recognizable for branding purposes.