Sift flour, baking soda, baking powder, salt, and spices into a large bowl and set aside.
Beat the egg yolks in a separate large bowl.
Mix the egg yolks with the buttermilk and half-and-half.
Add the sugar to the wet ingredients and stir until well-blended.
Add the sifted dry ingredients and beat until smooth.
Turn a portion at a time onto a lightly [WELL] floured surface and roll or PUT OUT to 1/2-inch thickness.
Cut with a 3-inch doughnut cutter OR a 3-inch biscuit cutter, then make a hole in the centre of each with a 1-inch cutter or the end of a wooden spoon handle.
In a heavy 6-quart pot filled no more than halfway with oil, heat oil to 365 degrees.
Fry doughnuts 45 seconds to 1 minute on each side until golden brown.
Drain on paper bags [OR rags or papertowels on a wire rack.]
[If desired, dust with icing [powdered] sugar, melted chocolate, or a glaze of icing sugar mixed with milk or lemon juice by the tbs.]