In a medium bowl, whisk together the mayonnaise, sugar, lemon juice, and vinegar until smooth and well combined. The acidity from the lemon juice and vinegar will help brighten the richness of the mayonnaise and prevent the dressing from tasting too heavy. I like to use freshly squeezed lemon juice rather than bottled—it makes a noticeable difference in the final flavor, adding a more vibrant acidity that balances the sweetness beautifully.

Add the salt, pepper, and onion powder to the wet mixture from Step 1, whisking thoroughly until all seasonings are evenly distributed and no streaks remain. Taste the dressing and adjust the seasoning to your preference—if you like it tangier, add a bit more lemon juice; if you prefer it sweeter, add another pinch of sugar. The dressing should be smooth, creamy, and well-balanced with no grittiness from undissolved salt or sugar.