Preheat oven to 375 degrees. Spray half a muffin tin with non-stick cooking spray.
Cut unbaked cinnamon rolls into pieces, about 9 pieces a roll. Stick pieces into the muffin tin wells and push them together.
Mix together melted butter, brown sugar, and vanilla. Pour mixture evenly over each muffin.
Bake for 14-18 minutes, or until golden brown and cooked through.
Remove from oven and run a knife around each muffin. Let cool for 10 minutes. While cooling, prepare frosting.
In the bowl of a stand mixer, add butter and cream cheese. Mix on medium, then increase to high or until smooth and fluffy. Slow add powdered sugar. Beat again on medium until sugar is well incorporated. Add lemon juice and milk and beat for 3-4 minutes, or until fluffy. Frosting should be slightly thinner than cupcake frosting.
Once muffins have cooled, slather frosting on the top of each muffin. Garnish with remaining pecans.
Serve immediately or store in an airtight container until ready to serve.