2 1/2 c cake flour (or 2 1/3 c all-purpose flour) .
1 tbsp unsalted butter .
1/2 tsp salt .
2/3 c whole milk, at about room temp (I've also used 2% milk with good results) .
1 1/2 tsps pure vanilla extract .
1 1/2 tsps baking powder .
3 large eggs, at about room temp .
2 large egg yolks, at about room temp .
3 tbsps cake flour .
1 1/4 c unsalted butter, plus .
1 3/4 c granulated sugar
Directions
Step #1 Position oven rack in the center of your oven & preheat to 350 degrees.
Step #2 Melt the 1 Tbsp butter & brush the entire inside of a 12 c Bundt pan.
Step #3 Put the 3 Tbsp flour into the pan & roll the pan around to distribute the flour; use more flour if necessary & knock out excess flour when pan is completely coated.
Step #4 In a medium bowl mix flour, baking powder & salt; set aside.
Step #5 Using a stand mixer with paddle attachment beat the butter & sugar on medium speed for 2 mins, until light & fluffy.
Step #6 Add egg yolks & beat on lowish speed until smooth.
Step #7 Stop mixer & scrape down the bowl & paddle.
Step #8 On medium-lowish speed add whole eggs one at a time, mixing at least 20 seconds between each egg.
Step #9 Stop mixer & scrape down again.
Step #10 On your mixer's lowest speed add half the flour mixture & mix until just mixd.
Step #11 Add milk & mix until just mixd.
Step #12 Add remaining flour & mix until just mixd.