In the scene where Miranda offers to finish Debbie's cake, Miranda calls Carrie to let her know she isn't going to the play, the clock behind Miranda shows 6:28, but shows 6:53 by Carrie.
While Miranda sees Steve baking cupcakes she says she will help. She makes it seem like she has never baked before but in Season 4 Episode 4 "What's Sex Got to Do with It", she bakes a Duncan Hines Devil's Food Cake.
When Miranda asks Steve how many cupcakes they are making for Debbie's birthday, he puts up his fingers and counts: "H-A-P-P-Y B-I-R-T-H-D-A-Y D-E-B-B-I-E, 20!" There are only 19 letters in that phrase.