I hear this is “just like at Texas Roadhouse” but I’ve only been there once and never had the cinnamon butter, so I couldn’t tell you. We love it on cinnamon swirl bread.
1 cup butter, softened
1/3 cup sweetened condensed milk
1/2 t karo syrup
2 t cinnamon, or to taste
Whip it really well. Store in fridge.