Pull out the eggs, butter, and yogurt and let sit at room temperature for 30 minutes.
Grease and lightly flour an 8"x4"x2.5" cake pan.
Preheat oven to 325 degrees F.
Place the butter in the bowl of your stand mixer and beat for a minute on high speed. Gradually add the sugar and let it mix on medium-high speed for 10 minutes. You'll have to scrap the sides of the bowl every once and a while. You're looking for a very light and fluffy butter mixture.
Once you're butter is light and fluffy add the vanilla and beat for about 30 seconds.
Add one egg at a time, beating for 1 minute between each egg.
In a separate bowl combine the flour, baking soda, baking powder and pumpkin pie spice. Sift together to combine.
Alternately add the flour mixture, Greek yogurt, and pumpkin puree to the bowl of the stand mixer. Remember to scrap the sides of the bowl occasionally to make sure it's being properly mixed.
Blend until the mixture is smooth.
Pour batter into prepared cake pan and bake at 325 for 65-75 minutes or until a toothpick inserted in center comes out clean.
Let cool in pan on wire rack for 10 minutes. Then remove the cake from the pan and let cool to room temperature. Once cake is completely cool, cover and let sit over night or enjoy right away.
Slice into 1/2 inch pieces and drizzle with salted caramel sauce. Enjoy!