"I have to tell you, every time we touched on the show it was static electricity," Davis, who plays Annalise Keating on How to Get Away with Murder, said. "Every single time it was black girl magic on steroids. I'm telling you!"
Davis told host Jimmy Kimmel she hopes her "sparks" with Washington, who portrays Olivia Pope on Scandal, will translate to the screen.
"I haven't [seen it yet]," she said of the episode. "I'm hoping."
How to Get Away with Murder and Scandal were both created by producer Shonda Rhimes. Rhimes confirmed the crossover episode in a tweet this month, with Washington later calling the collaboration a "dream."
"It's a little bit of a dream come true," the 40-year-old actress told Entertainment Tonight at the Golden Globe Awards.
"The fact that I get to do scenes with Viola Davis is such a dream come true because she's such a hero of mine," she added. "We've done a lot of press together for Shondaland, but to be able to work together is pretty phenomenal."
The How to Get Away with Murder and Scandal crossover episode will air March 1.